A device can only be in one of 2 states, on or off. If you strip away all the fancy programming languages, underneath all of that, at a very low level, your computer uses binary. A series of bits that are either on or off. 1 or 0. the computer then cleverly turns all these 1s and 0s into all of the oprgrams and operating system parts and pieces that make everything a bit more user friendly. Computers think in binary. Its just what they do. But whemn it comes to quantum computing, it’s ot quite so simple. It’s easy to say that quantum computing will be the next big thing in the field of data processing. A quantum computer may be able to manipulate individual atoms and even molecules for data storage and processing. Not to mention that a quantum computer would introduce a new 3rd state for its special data blocks called “Qbits” that could be 0 1 or both simultaneously. In whats known as a superposition. Qbits will enable quantum computers to perform some very exciting functions, like speeding up data processing dramatically. By working with all possible combinations of bits simultaneously, thanks to quantum entanglement and quantum tunneling. Quantum computers will run laps around our current machines, using Qbits to achieve ludicrous volumes odata and opening up a universe of possibilites when it comes to crunching numbers. They will prove instrumental good ness that li fi will bring to the table. Not to mention mimicking the vast data processing abilities of the human brain. But what role will an artificial brain play in the fiuture?No one knows when Qcomputers will be made available to the general population. One company Dwave even claimed to have built the first fully functioning Quantum Computer but we’ve still got a long way to go until we have quantum computers in our homes. Nanotechnology Quantum Computing Global Communications Network, the center’s mission is to develop the science and tech for a global quantum information network, and that means building ultra fast quantum computation and ultra secure quantum communication, basically have 3 programs. 1) to develop a silicon quantum computer using electrons as the quantum bit, the Qbit. 2) to develop an optical quantum computer where we use photons of light as the Qbit. 3) we want to develop quantum communication as to develop absolute secure communication, and then adress the critical challenges of extending the communication distance and make it very fast. So what is a quantum computer anyway? Dr. Andrea Morello at the University of NSW. We want to mae a new type of computer where the bits are not just normal transistors that switch on and off, but a more complicated quantum mechanical system that can be on or off or both at the same time. That’s what quantum mechanics allows you to do, make quantum superpositions, the physical system we’ve chosen to create for quantum bits is based on single electrons confined in a silicon nanostructure. The first technology for us is really to mae single atom devices for conventional computing and see if you can take moore’s law all the way down to the atomic level. That has implications for industry now. Can you npush these devicessmaller and smaller, but what we’re really aiming for is to make a quatum computer and predict to get this exponential speed of computational power, and thats the holy grail, can you make ot encode it into a computational. Building a single atom device is conceptually simple, however it requires the ultimate technological control. Researcers at the center for quantum computation and communiucations technology use scanning probe microscopes to control the placement of individual atoms into a silicon device. Having world leading equipment and state of the art cleanrooms, are absolutely pivotal to the research. The key advantages to optical quantum computing is that the photons carry the quantum information very well wiothout degrading it, they’er also bevery mobile so they move the information around the quasntum computer very easily and also talk to classical databases very easily, use a laser to read out information in CDs and DVDs. Nanotechnology Documentary Quantum Computing, what it is, how it works. There is a limit to how many transoistors you can cram on to a single chip, so moore’s law will end eventually. This might even be a rebirth of analog computing for solving certain kinds of problems. Q computers work on the type of probles that cannot be soved by classical digital computers. It would take more than the lifetime of the universe to identify the forward state of a protein and yet nature can do it in seconds. If we could simulate 20 years of evolution in 10 nanoseconds, then we could much more succesfull than we are now. Superposition means the system is in some mixture of the 0 state and the 1 state. A quantum computer can paralell process all these multiple possibilities. The trick is to build it based on quantum physics, the phsycis of the very small, rather than classical physics, the phsycis of the large world we see around us. Whenm you get down to smaller scales things become probablistic, things interact with different physical effects than the ones we can see on the large scale or those physical effects manifest themselves in different ways. Quantum computers exploit probabilistic phenomena in a way that makes a new kind of problem solving possible. I don;’t know if you niotced, but there’s a new wave of computer technology beign quietly developed in basement labs and secret company offices. Im talking about quantum computing. Companies like google, microsoft and IBM and the US govt have started investing heavily in the development of quantum computers in the last few years. And news of their investments is slowly leaking out in the mainstrea media. so what is the quantum comouter and why are allm the major powers that influence our lives interested in them? The short answer is they promised to be faster safer and better at solving certain kinds of problems than our trusty laptops, but thats only one part of the quantum picturee. Let’s figure out what it means for something to be quantum. Sometimes quantum is used itnerchangeably with “small”, but that’s not really accurate. Quantum things are hapening on all length scales all the time, the distinction is that the likelihood that we notice these corrections on top of newton’s classical physics decreases rapidly the bigger we get. A the quantum level a particle can teleport, travel backwards in time, be entangled with a distant cousin, and a pothetical cat in a box can be both alive and dead at the same time. This apparently fantasctical behavior is all possible because of physics, most relevant to our quantum computing plot is the idea of “superposition”, whioch transcends classical deterministic outcomes “alive or dead”, “heads or taikls”, “zero or one”. Describe these states as a distribution of probability. The cat has a 70% prpbability of being alive. and as a funny outcome of the science we dontget a fixed ansewer, until we open the box and observe the cat, take a measurement of the system, or otherwise it for specific output. A computer capable of exploiting this and other quantum properties like entanglement would not be constrained by a classical computer’s need to perform calculations sequentially because quantum bits would be capable of existing in a probability of many states, and thus be much better at tasks like simulating molecular bonds, performing rapid searches of complicated databases or factoring large numbers very quickly. These examples may seem silly or irrelevnant until you learn that factorization is prohibitably time-consuming for a classical computer, which is why it forms one common approach to data encryption. Now quantum computers are looking pretty good, escpecially if you have an interest in national security. So how close are we to a programmable quantum computer? Not that close. You’ll probably use one in your life time but doint run out to the store to find one just yet. Research in this area is happening at a rapid rate and its even resulted in the nobel prize for physics in 2012, but scioentists still have a long way to go. Challenges arise both in the difficulty and control and manioulation of quantum states, something that makes encoding quantum information very difficult, as well as the viulnerability of that information to distrubance from the environment. Nevertheless scoientists like those at Caltech’s institute for quantum information and matter, are working at the cutting edge of our current knowledge to make quantum comouting a reality. As for it’s opotential, being able to simulate molecular interactions to create optimized materials on demand seems reason enough for google , microsoft and IBM to throw tons of money at quantum computing, whereas one scientists recently reminded me, who would have been able to forsee the impact of facebook or the internet when classical computing was in development. Researchers at the university of New South Wales in Sydney have just created a kind of quantu logic circuit out of silicon, clearing the way for actual quantum computers, we’re not just taling about it, we can actually build one now. Quantu computers are exciting because they can carry out multiple computations at once. This wont make browsing the intenet any faster but it will let drug companies test all possible outcomes of differe tchemical combinations at the same time, which could make discovering new drug treatments exponentially faster. But how would a computer like that work? Well the fundamentals would be kind of the same as they are now, the computer or phone or teblet you’re using renders data in binary bits, the bits are binary because they can only be in 1 of 2 states, 1 or 0. So if you have 2 bits they could be in any of the following positions, 00, 01, 11, or 10. Those are all the 4 combinations you could make out of 2 bits. While each bit CAN be in any of those positioons, they are only in one of them at a time. In a quantum computer, 2 bits could be in all 4 of those positions at once. How? Well if you’;ve ever heard of shrodinger’s cat, the same logic that applies tot he cat applies here. In conventional computers, bits are encoded by circuits that are either on or off, one or zero, by using an electrical current which is just a flow of electrons, but quantum cpmpiuters could use quantum bits called “Qbits” by using a single electron. And unlike a digital circuit, an aelectron can be doing all sorts of things at once. A single electron miught ewither be spinning in alignment with the nearest magnetic field or spinning perpendicular to it. But until you measure the electron, it’s actually doing both at the same time, it doesn’t have a defined state. This is called “quantum superposition”. But you still have to measure the spin to get a value for that qbit so you’re still going to get a one or zero. But by measuring it in paralell, you can get multiple values for a single qbit at the same time. So with 2 Qbits wired together you can get more values and if you have 3 qbits you can have 8 and so on. But making actual circuits with qbits is incredibly hard. What the new south wales team maneged to do was boil down all these ideas to create a “quantum logic gate” 2 qbits that could interact with eac other. Logic gates are the basis of any digital circuit, they take data from bits, apply programmed logic to the information and then output new data based on the result. So the team took the existing technology and a silicon microchip and reinvented the transistor, the tiny switch that turns on and off to create ones and zeros. But instead of being controlled by ciurrent or a flow of electrons, it’s transistor basically trapped a single electron and stored its spins as information, they then used microwaves and electrodes in the chip to change the spin of one electron and therefore the information in that Qbit. That information then changed the state of the qbit it was connected to. The result was a sort of quantum “if-then” command. Where the state of one qbit depended on the state of the other, the researchers then worked out how to scale up this design from 2 qbits to a hundreds or potentially millions, and they’ve patentied this design based on the same manufacturing methods that are used to make microchips today. So quantum physics is weird but quantum computing would be amazing. You can use the weirdness of quantum computing in 2 main ways. First you can encode more informationn in a Qbit than in a conventional bit. 2 conventional bits for instance will have 1 or 4 possible values. 00, 01, 11, or 10, each qbit though can be both a zero and a one at the same time. So 2 qbits can be all 4 possibilities at once. As you add more qbits the amount of information you can stor and process goes up incredilby fast. With a 300qbit computer you could do more calculations at once than there are atoms in the universe. Basically a big enough quantum computer would be infinitely more powerful than the best supercomputer we could ever build the regular way. And its why physicists have been geeking out over this ever since they realized it was theoretically possible. The 2nd main advantage of quantum computing is that you can use qbits to send information in a way thats inherently secure. Whe you encrypt information you jumble it up so that when you send it, anyone listening in wont be able to decipher the message. In theory this could be hacked, but quantum computing on the other hand may be the perfect answer because of another werid rule of quantum mechanics, when you measure something like an electron spin, the act of taking the measurement actually changes some of the electron’s properties. So i9f you use qbits to send your friend bob a key and your arch nemesis eve intercepts any of the particles before sending them to bob, you and bob will be able to tell that someone messed with theqbits before he got them. This means no one can evesdrop on your key without you knowing about it. This is next order encryption and we’d like to take advantage of it, but that would mean having more than one quantum computer and hooking them up over long distances. Basically we want to build a quantum internet, and that’s where this new research comes in. We already have a massive global network of fiber optic cables so it’d be great to piggyback on our existng infrastructure as we build the internet of the future. And fiber optic ables are a pretty good choice because you can use photons of light as qbits. But there are 2 big challenges, first, to use those fiber optic cables, you need to transmit photons with a certain wavelength, and second qbits are super fragile, if anything interferes with the particles before you transfer your message, you’ve lost your data, so you need to keep your qbits stable. We’ve already discoverred how to use certain materials to store quantum information for long enoug to send it troug a network, but they dont work on the right wavelength for our fiber optic cables. And the materials that ARE compatible with those cables can store information for onl a fraction of a second. To solve this probelm the Australian team wanted to find a way to lengthen that time. So they started experimenting with a crystal that had some Erbium in it, Erbium is a rare earth metal and a crystal with Erbium ions in it can work on a wavelength that matches fiber optic cables, but they can only store quantum information for short bursts. To increase that time frame the group applied a super strong 7 tesla magnet, thats the strength of the most powerful MRI machines. Magnets are helpful because they can freeze electrons in the crystal in place, which keeps them from interfering with and destroying the data, and it worked! The magnet increased the crystal’s storage time to 1.3 seconds. Now that might not seem like very long, but its a 10,000x fold improvement over what scientists could do before and that’s good enough for quantum internet. Other experts have estimated that with quantum repeaters to boost the signals, you need storage times of just one second to send messages 1000 km. So where’s our quantum internet? Well any kind of widespread network is still a ways off. For one thing the australian setup requires very low temperatures to work, 1.4kelvin or -272 celsius, that’s cold. And seriously expensive to maintain. And of cours there’s that strong magnetic field. The researchers think their material will still work with a less powerful 3 tesla magnet, but its not like that’s nothing. Think of a more typical MRI machine instead of the most advanced. Not exactly chump change. But even if we solve these problems, quantum networks might never be used for things like watching videos or execute run of the mill google searchers like “Quantum repeater” or “Erbium Crystal”, there’ll be reserved for super secret situations. When you want your communication to be absolutely secure. So maybe you’re banking, but probably more like high level internatiaional intelligence. Basically spy stuff, but no matter who ends up using it, the Quantum internet will be a major upgrade for the world of Cryptography. Quantu, computing which uses the princioples of quantum physics to let computers try ALL of the possible solutions to a problem at the same time and then choose the best one. Last week Google announced that it’s building a quantum computer designed by a company called “D-Wave” at NASA’s Ames research center in silicon valley. And at nearly the ame time in 2013 govt scientists at Los alamos national labs in new mexico have developed a super secure quantum network. Quantum computers have been a cool idea since the 1970s, but theyve been hard to actually develop because they draw on the concept of quantum mechanics which can be weird. One concept is superposition, the idea that one particle like an electron can exist in many different theoretical states or configurations at the same time, but can only be observed in one state. But it can be hard to link together big objects and quantum objects to make them work together, and its hard to make a computer obey those laws. But scientists have pulled it off using things like phoitons as information units instead of traditional bits. While bits can only carry data by assuming avalue of either zero or one, photons can exist in many states simultaneously, meaning they can hold a lot moe information. When used as information units, photons get their own special name “qbits”, but the trouble with qbits is another one of the fundamental principles of quantum mechanics, when you actually observe something like a particle, it can only be in a single state, so while a photon can exist in several states at once and thus hold a ton of data, as soon as someone tries to read that data, the photon basically becomes either a one or a zero. This makes quan tum computing tricky but it also has some very useful implications. Because as soon as somebody tries to look at a qbit, it basically becomes unreadable., which makes it the ultimate in computer security. The challenge then is how do people who are actually allowed to read the quantum information get at it if you cant read it? The solution seems to be “indirect observation”. The computer itself interprets the quantum message and turns it into a traditional binary message once the qbits have done their job. So for the secured communication system that los alamos labs invented using quantum computiong this means creating a one time readable message. Not perfectly secure but pretty darn safe. And for google at NASA’s computer, this means the qbits can run incredibly complicated programs and models very quickly but still give the user a comprehensile binary answer. This seems to be the real potential payoff of quantum computers, doing really complicated stuff all on their own, learning to tackle many faceted problems with nuanced returns, analyzing patterns, recognizing shapes, voices, all without help, great for AI. Google and NASA hope this tech will lead to huge advances in AI, meanwhile scientists at los alamost think it could be the key to the future of cyber security. The future is already here,in 2013 aerospace company Lockheed Martin bought the very first cmmercial quantum based computer from D wave to help design jet engines and satellite systems. So it could be that in the next decade or so you’ll be watching ME on a quantum device that’s infinitely smarter than the old bit chomping thing you’re usiong now. Its also possible that i’ll have just been replaced by one of them.
Moore’s law is ending and computer parts are approaching the size of an atom. To understand why this is a problem we must realize a compute ris made of simpe components doing very simple things 1) representing data, 2) the means of processing it and 3) control mechnaisms (1,2,3: main memory, arithmetic unit, control unit). Computer chips contain modules, which contain logic gates, which contain transistors. A transistor is the simplest form of a data processor in computers, basically a swtich that can either block or open the way for information coming through. This information is made up of bits which can be set to either zero or one. Combinations of several bits are used to represent more complex information. Transistors are combined to create logic gates, which still do very simple stuff. In a nutshell a transistor is just an electric switch and electricity is just electrons moving from one place to another, a switch a passage that can block electrons from moving in one direction. Today a typical scale for transistors is 40 nanometers, which is about 8 times less than the HIV virus’ diameter (120nm) and 500 times smaller than a red blood cell (7µm). As transistors are shrinking to the size of only a few atoms, electrons may just transfer themselves to the other side of a blocked passage by a passage called quantum tunneling. In the qua ntum realm physics works quite differently from the predictable ways we’re used to and traditional computers just stop making sense. We are approcahing a real physical barrier for our technological progress. To solve this problem, scientists are trying to use these unusual quantu properties ot their advantage, by building quantum computers. In normal compouters, bits are the smallest units of information. Quantum computers use qbits which can also be set to one of 2 values. A qbit can be any 2 level quantum system, such as a spin in a magnetic field, or a single photon. 0 and 1 are the system’s possible states, like the photon’s horizontal or vertical polarization. In the quantum world, the Qbit doesn’t have to be in just one of those, it can be in any proportion of both states at once, this is called “superposition”, but as soon as you test it’s value say by sending the photon through a filter, it has to decide to either be vertically or horizontally polarized. So as long as its unobserved, the Qbit is in a superposition of proba bilties for 0 and 1, and you can’t predict which it will be. But the instance you measure it, it collapdses into one of the definite states. Superposition is a game changer. Four classical bits can be in one of 2^4 different configurations at a time, that’s 60 possible combinations out of which you can use just one. But qbuits in superposition can be in all of those 16 combinations at once. This number grows exponentially with each extra qbit. 20 of them can already store a million values in paralell. A weird and unintuitive property qbits can have is entanglement, a close connection that makes each of the qbits react to a change in the other state instantaneously, no matter how far they are apart. This means that when measuring one entangled qbit you can directly deduce properties of its partners without having to look. Qbit maniupulation is a mindbender as well. A normal logic gate gets a simple set of inputs and produces one definite output. A quantum gate manipulates an input of superpositions rotates probabilities, and produces another superposition as its output. So a quantum computer sets up some qbits, applies quantum gate to entangle them and manipulate probabilities and finally measures the outcome, collapsing the superpositions to an actual sequence of 0s and 1s. What this means is that tyou get the entire lot of calculations that are possible with the setup all done at the same time. Ultimately you can only measure one of the results, and it will only probably be the one you want, so you may have to double check and try again. But by cleverly expoiting superposition and entanglement, this can be exponentially more efficient than would ever be possible on a normal computer. So while quantum computers will probably not replace our home computers, in some areas they are vastly superior. One of them is database searching, to find something in a database a normal computer may have to test evry single one of its entries. Quantum algorithms read only in the square root of that time, which for large databases is a huge difference. The most famous use of quantum computers is ruining IT security. Right now your browsing, email, and banking data is being kept secure by an encryption system in which you give everyone a public key to encode messages only you can decode. The problem is that this public key can be used to calculate your secret private key, but doin gthe math on any normal computer would literlaly take years of trial and error, but a quantum computer with exponential speedup can do it in a breeze. Another exciting new use is simulations. Simulations of the quantum world are very intense on resources and even for bigger structures such as molecules, they often lack accuracy. So why not simulate quantum physics, with actual quantum physics? Quantum simulations could provide new insights on proteins that might revolutionize medicine. Right now we don’t kn ow if quantum computers will be just a very specialized tool or a big revolution for humanity, we have no idea what the limits of technology are and there’s only one way to find out.
Q computers can be used for data encryption, which relies on working out waht the prime factors of a large number are. We have 2 prime factors to remind you, prime factors can only be divisible by itself or one, if you times 2 numbers together its a very easy problem, but if i want to work out what the prime factors of a large number are, it’s actually a very difficult problem, rather like the one I just showed you. This underlies the difficulty of the problem underlies data encryption. So we encode our information, a very large number, and we give somebody one of the prime factors as a key so they can decode the information on the other side. If they don’t have the key though they have to work out what the prime factors are and its very difficult. Another examples. Aniother thing Q computers are good at is searching large databases sorting through large amounts of information, or for modelling systems where there’s lots of variables. So we can imagine climate modelling, modeling in the economic system, we can start to imagine how chemicals and reactions form, and how new things start to evolve, how the human body forms. Where quantum computation will take us is something we don’t know, but it had huge potential. As a consequence there’s a massive international race to build a quantum computer.
You may have heard the news that Google’s AI lab recently announced it had developed a Quanntum computer capable of solving a certain type of mathematical problem over 100 million times faster than a single core processor. So what actually is a quantum computer? Its a computer that takes advantage of the weird physics of quantum mechanics. At that level things behave differently then you’d expect on a classic marco level. Classic computing relies on bits, ones or zeros. Quantum computing relies on Qbits. We’re talking about zeros and ones at the same time, by bundling these together and applying them to something called a “quantum gate”, you can solve problems in a massive parallel process instead of in sequence, and that saves a huge amount of time. So does this mean we’re all going to have these super mega powerful computers in a years time? Not quite. Quantum computers, for one thing, google’s quantum computer has a processor that’s lowered down to a temperature that’s just above absolute zero, and you’re not gonna find that in an average laptop. For another, they are really only good for certain types of problems, like optimization problems. The classic example is the travelling salesman. You’ve got a salesman who has to go to various cities and you want to figure out the most efficient route. But everytime you hit another city, the problem gets more complex. If you were to feed this to a classical computer with a straightforward algorithm, it’d go through every single possible option, then compare all the results at the end, which could take centuries. And by that time your travelling salesman has ceased to be. But the quantum computer uses a different methodology caled quantum annealing. The term annealing refers to how metals cool down. When they’re hot, molecules are bouncing all over the place, but as the metal cools down, the molecules settle into low energy states, quantum annealing does the same thing but on a quantum level. It basically uses quantum mechanics to determine the lowest energy state and that’s your answer, it’s which ever solution uses the least amount of energy, that means its the most efficient or cheapest, in the case of the travelling salesman. Google’s computer was able to solve this optimization problem much faster than a classical computer, so case closed right? Not quite, the classical computer was using an algorithm called “simulated annealing” and people have pointed out that if had used a different algorithm it may have performed as well or better than the quantum computer. But this does put us one step closer to true quantum computing and that can really transform our world in many ways. Ex: Cyber security. QCs are A potential breakthroug tech that may have virtually unlimited applications. But unfortunately, like a lot of technology, especially anything with the word “quantum” in it, quantum computer has picked up a lot of myth and not a lot of clear explanation. The confusion gets exasterbated a lot by both terminology and the tendancy of “quantum” to attract both bad explanation from folks who don’t understand it as well as they should to be explain it. If you’ve ever watch any explantions before, you might have heard the term “superposition” for instance. The Qbit or Quantum bit, is the basis of quantum computing mucha s the bit is for classical compouting. And just as 8 bits makes a byte, 8qbits makes aQbyte. But whereas a bit can only be zero or one, a qbit can be a zero, a one or anywhere in between that. A classic byte has 8 bits, can be any of 2^8 or 256 possible permutations, typically this is the smallest bit of adressible memory, because it can be one character, a number, or a symbol. So you could store any number, letter, or symbol on a byte. But on a Qbyte you could in theory be storing all 256 of them at once. Of course when you go to look at that Qbyte it would collapse its states to one specific letter, and presumably a random one. Which would seem to make it not very useful. What’s useful is on the calculation side. A classic computer uses bits and logic gates to do calculations. A quantum computer using quantum logic gates does that too. But while the classic computer would perform one calculation off that one set of digits, the quantum one is going to calculate those digits too, all of them. Hard to picture if you’re not familiair with core concepts of computing, so let’s use our box analogy, only this time it’s a room not a box, and I stick a person inside it. And what our random objects is going to be is 2 numbers, each between 0 and 9, each selected randomly. I tell the person that when I see those they are to multiply them up. I close the door and hit the quantum switch and 2 numbers pop up. We now have 100 states. One with a person saw two zeros and got a zero, one where it was a 1 and 0 and they got 0, one where it was 0 and 1 and they got the same, and so on, all the way up to 9×9=81. 100 simultaneous states and calculations all going on in that room. Until I open the box and 99 of those states collapse, leaving one state that remains. 6×7=42. Now how would that be useful? I’m going to strech the science here a bit to make it intuitive. Analogies for quantum are always a bit iffy. So imagine if I told that person that if they got 42 as an answerm they should open the door and step outside, there’s only 2 people who come walking out that door, the one who got 6×7 and the one who got 7×6. Now imagine I had a spreadsheet with 2 columns. Name and phone number. Thousands of names and numbers but somebody jumbled the sheet, names are not longer linked to numbers. Ive got a hard copy phone number, Ive got someone’s phone number but i dont know the nname attached and need it quick. I could rig up the room and quantum switch so it randomly picked and displayed a name on the wall. Then i could send someone in with a phoen book and ask them to look up the random names. And if it matches the phone number i’ve handed them on entry, to step outside and give me that name. They steop in and the quantum event goes off and displayes a truly randomly selected name out of my spreadsheet. Instantly the room is jumped up to tens of thousands of states and superposition as that person is looking up every single name at once. But a few moments later only one of them steps out that door, and its the one who had the right name for the phone number, to him that was freakishly good luck, just happening to get the name that macthed that phone number. That’s a big application for quantum computers. As a search method it looks up every value but only the state that was correct. Which found the right entry. If ou do it right, the analogy i used wouldnt work in practice beyond macroscopic examples of quantum like the cat in the box not really being practically viable, the human is a very complex machine, which themselves operate close enough to the quantum level that random stuff probably can spill out. Consider, one of our states is the guy in the room getting srved the right name for the number. But with something as complex as human thinking, another one of those states would be getting the name right before that number and seeing the desired number right below it. A second chance tio be right, which is fine, but they might also accidentally think that was the number for their name, jot that down and exit. Ditto someone might get a name that had a phone number 1 digit off or transpose and write that down and exit. Another might pat themselves down for their pen, miss it, and step out. Another might step out to tell you about the funny coincidence. In quantum anything which CAN happen has a probability of happening, and would have a state in that superposition. It might be incredibly tiny, but there’s always a risk of error with a quantum computer, and it’s going to be a lot higher with a giant complex system like a human in a room. You only get to see one state, and you want a system where the right answer is 99.99999% lilkely to be the one you’re shown. It is very unlikely that the guy is going to walk out of the room to inform you that his pen and paper, underwent spontaneous quantum weirdness and turned into a slice of cheesecake. It’s possible but absurdly unlikely. So we’re not concerned about that one. But its quite likely they might make an error when looking at their name and comparing it to the desired phone number. The key thing though is that a quantum computer that no classical computer coulnd’t possibly do, even a giant matrioshka brain. A matrioshka brain couldn’t search the library of babel and find shakespeare’s Tempest in it, but a quantum computer could. Similarlty, there are certain types of calculations, like prime factoring, it can be very fast at. Any integer can be displayed as the product of various prime numbrs. For instance, 15 can be factored into 3 x 5. 105 can be broken down to 3x5x7 and so on. I could pick a bunch of prime numbers and multiply them together pretty quickly to produce some huge number, but it would take far longer for someones to take every prime numbe rthan that number and try to factor it. As you go through all the possible combinations. It’s not very hard to produce a number that even the biggest classical computer could not prime factor in less time than the lifespan o the universe. But the quantum computer can try each combination randomly and also simultaneously and pop out the answer almost right away. We use something like that for our encryption methods, because a system which can theoretically be broken but would require every computer we have to work at it for trllions of years, is seen as “safe enough”. And that is why people talk a lot about quantum computers foiling our encryption methods. That’s not exactly true, but it can beat THAT encryption method, so you have to use a different one that’s safe against it. Quantum computers capable of soing that are a long way off. Quantum computers are also not magic wands, they do have limitations, and right now tons of them, because it is very hard to keep tons of atoms entangled with each other, and you want to be very careful extrapolating amazing abilities off the human in a room example I gave, because that was just for conceptual purposes. As I mentioned, there are a lot of problems using that. Even if you could set up that person in a box and realistically you can’t, but even if you could get that to work, you cant just take someone, toss them in the box and tell them only to leave if they figure out the ultimate answer to life, the universe, and everything. You have to create a scenario where the correct answer is the most likely state for you to observe. And preferably so much more likely that the odds of observing a wrong one are nearly zero. I mentioned factoring a moment ago and gave the example of 3×5=15. It was a huge deal a few years back when they managed to do that simple factorization. Less mentioned was that they ran it thousands of times and it got the right answer 48% of the time. And Shore’s algorithm, the one used for quantum factoring, holds that it’s only going to get it right about half the time anyway. It was a huge technological accomplishment, and we’ve done better since. But it is important to keep in mind how far this technology has to go before it’s useful even for niche applications. And the main school of thought is that there’ll always be tons of applications that classic computers remain better at. In a nutshell, what quantum computers are good for is searching for needles in a haystack, patern matching, and the kinds of problems that involve a lot of trial and error. And for all the bits or atoms or photons, the device will tend to be bigger per Qbit than a traditional computer’s bit, because trying to keep a ton of atoms entangled to each other is a bit of a nightmare, and its frankly amazing they’ve gotten up to 2000 Qbits. It would be very to shrugg and assume Moore’s law will apply to quantum computers too. It may well be that quantum computers with billions of qbits will emerge 40 or 50 years down the road. As such moore’s law doublings would imply. But we could easily bottleneck. When you start thinking about technology inevitably progressing on time table, you’re not doing science anymore. But we have no idea how big we’ll be able to make these and how long that will take, nor are the applications it might have. Plenty of people predicted enormous computers capable of billions of operations back when we were at this stage of classical computing. But we all know modern personal computing and the internet is nothing like what they were predicting. We all know what most people use the internet for, and Im pretty sure alan turing never expected us to use computers to exchange pictures of cats. So we dont know all the applications we will have for quantum computers as they get better. But we CAN expect to find plenty of applications for them besides the ones we’ve thought of so far, its just too soon to tell and they are very promising technology. At the same time they’re not without their limitations.
Quantum computers are not based on turing type technologies, they compute on individual atoms. We are begging to sputter with regards to more and more computer power. Moore’s law, which has held for 50 years, which says computer power dobules every 15 months, may begin to expire in the next 10 or so years, in other words, if you knew that at christmas time, your computer was just as powerul as the last christmas presernt? Would you buy a comouter or upgrade? Most people won’t, if a new computer is identical to last years model. Well that could create a planetary recession or depression, knowing that this engine of prosperity, the computer revolution is running out of steam, but that’s just the way it is. In 1980 Russian-German mathematician Yuri Mainen, was the first to propose the idea of quantum computing. A year later, eminant physicist Richard Feynman presented a logical quantum computer model at the conference on physics and computerization. The premise behind Feynman’s model rested in the conviction that it’d be impossible to conduct a simulation of a quantum system with the use of a classic computer. Feynman understood that the traditional engineering approach ton the problem of computer development would never lead to a revolution, he based his reasoning on the laws of nature. Feynman’s lectures from the last years of his scientific activities are considered by many to be a key moment in the development of quantum computer theory. Classic computers are devices that with the use of transistors, process information in the form of sequences of various combinations of 0s and 1s, known as computer binary language. In simple terms, a transistor is a type of switch, it can be turned on, which corresponds to binary 1, or it can be turned off, which corresponds to binary 0. The grouping of transistors into special circuits called logic gates, allows the computer to perform calculations and make decisions in accordance with the man-made computer program. The computer’s processing power depends on the number of transistors used. According to Moore’s law, today this power is doubling every 2 years. As of 2014, the commercially availabl;e processor, processing the highest number of transistors, is the 15 core Xeon Ivy Bridge E-X with over 4.3 billion transistors. In the case of graphic processors, the world’s record belongs to NVIDIA which offers computer acceloratoirs, in which the number of transistors excees 7 billion. Although this type of device is admirable, and undoubtably contributes to the development of science and technology, it does not change the fact that there are still some probelsm of higher rank which could not be resolved in optimal time, even by the most classic computers. No conventional solutions or improvements can compare with the endless possibilities offered by the laws of quantum mechanics.The quantum mechanical states of elementary particles, like transistor voltages can be described in 0s and 1s, depending on the method used we can apply various kinds of aprticles to the calculations. Here the state described by the 0s and 1s is the angular momentum of the propety known as “spin”. Although its not possible to describe this aprticlular feature through the use of classical mechanics, it can be likened to a magnetic bar capable of deviations. When the bar is pointed up, the state can be described by a value of one. However, when it is pointing down, it can be described by the value of 0. In other words, spin up corresponds to the turned on switch, and spin down corresponds to the turned off switch. Using this analogy, we can describe the defined quantum states with the use of binary systems much like a classical computer, however beyond this point all similarity ends. The adcantage of quantum computing mainly rests in the quantum mechanical feature, thanks which an elementary particle can be in multiple states simultaneously. This type of phenomenon called “superposition”, occurs before the measurement that defines the particle’s permenant state. Befor ethe measurement, when there’s no surrpunding noise, the elementaryn particle experiences superposition, manifesting its quantum ability to occupy multiple particle states at the same time. Thus in accordance with the principles of quantum physics, a spin of exemplary particle may, in a parallell manner, indiciate all directions at the same time. Forcing us to describe it with 0 and 1 simultaneously. Thus, unlike the classic compute,r where the basic unit of information is one bit, express by just one number in binary notation. In the case of quantum computing, information is expressed through a quantum bit, i.e so called Qbit, which is described by both zero and one binary units simultaneously. Wortking with Qbits provides us with incredible new possibilities for the effective processing of databases beyond what we could have ever before imagined. To better illustrate the advantage of Qbits, lets consider the example of all popssible combinations of the 2 bit data system, we have 4 possible states, 00, 01, 10, and 11. A two bit classic comouter can at the most simultaneously perform one of these 4 possible functions in order to check all of them, the computer would have to repeat each operation seperately. A 2 qbit quantum computer due to the phenomenon of superposition, is able to analyze all of these possibilities at the same time in one operaton. This is due to the fact that 2 qbits contain information about 4 states. While 2 bits only contain information about one state, thus a machine with n qbits can be superposition of the 2^n states at the same time. A 4qbit computer could analyze 16 parallel states in a single operation. In comparison, a 4bit classic computer can only analyze one state. To achieve the same solution as the quantum computer, the classic computer would have to repeat this operation 16 times. The advantages of quantum computing will continue to increase with increase in data. It is thus possible that a 5000 Qbit computer could one day analyze more data than there are atoms in the observable universe. To develop a fully efficient quantum computer, cetratin requirements must be fullfilled. One of the most important is toi create a appropriate conditions under which it would be possible to manipulate qbits while allowing them to maintian their unique properties. Its a very difficult task that requires great percision and special equipment, but doing so would give a way to a plentidue of possibiolities offered by the fundamental laws of nature. But there are still many obstaceles to the development of quantum systems. One of the biggest problems faced by scientists working to develop quantum computers is the issue of decoherence. Each elementary particle is subject to wave-particle duality, meaning sometimes it behaves like a particle and other times it behaves like a awave. The particle behaving like a wave is subject to a phenomenon known as “unitary evolution”, ewhich is described by shrodinger’s equation. Its a state in which noise from the surroundings, i.e deihenerence related to among others, thermal energy is not sufficiently large enough to trigger the leakeage of very susceptible quantum information. Such evoluion of entanglement and mutual decoherence may be analyzed and controlled in time. Which allows for the processing of information in a completely new way. Additionally it is essential that the qbts remain in a state of quantum entanglement only with each other, forming a coherent system in which the exchange of quantum information may occur between them. Unfortuanately our surrounds are comprised of elementary particles which only serve to disrupt the precision of quantum processing. Such uncontrolled entanglements of qbits with the surroundings ouitside the system could lead to a leakage of important information. Consequently, its essential to isolate and cool the quantum computer processor where the calculations take place. The cooling of the processor to extreemely low temperatures near asolute zero helps to calm the qbits by propelling them into a state of extremely low energy levels and, as a result, makes them easier to control. Cooling is also important due to the fact that some of the superconducting materials used in the construction of quantum processors and their unique processors can only be used at very low temperatures. Aside from nuclear magnetic resonance, other solutions and phenomema may be used to create a quantum computer. Such as, the polarization of light, Bose-Einstein condesate. Quantum dots, Ion traps, or fullerenes. Regardless of the method used, the goal is to achieve the capability to control quantum states in such a way that it’d be possible to progrram the computer, perform the calculations, and finally, read the desired result. In 2012, scientists from the university of New South Wales created the first single atom transistor made of silicon, in light of the many positive and interesting results of the research on the control of quantum states, team of australian researchers led by Michelle Simmons, has garnered world wide recognition. The entire computerization process in this type of model is based on the probabalistic method of what’s know as “Quantum Annealing”. Which consists of finding the optimal values among all possible solutions. Dwave’s first client was an american Armement scompany by the name of Lockheed Martin, which in 2010 decided to purchase 128 qbit DWave-1 computer for 10 million dollars. In 2013, with the cooperation of google, NASA, and URSA, D-Wave created a 512 qbit DWAVE-2 computer for an AI laboratory. Researchers in this laboratory are using it to facilitate them in their work such as the improvement of voice activation device technology, development of new drugs, climate change modelling, optimization of traffic control, development of robotics, and machine navigation and shape recognition. However, within the scientific community there’s a continuous and lively debate over the question of whether the computers manufactured by this canadian company can actually be considered as fully quatum. One of the basic allegations proposed by the criticis is the possible absence of quantum entanglement occuring between qbits comprising the D-Wave porcessors. However according to most recent published scientific studies, the computer definition used by Dwave is correct. Only time will tell whether this information is definitive. In order to take advantage of all that is offered by the laws of nature, we need software and algorithms, which are just as necessaary as basic construction elements. Creating algorithms however is a very difficult taks, as it requires that we take into account the counterintuitive laws of quantum mechanics. Never-the-less there are many people have risen to the challeng.e Peter Shore and Love Grover are the creators of some of the most well known quantum algorithms. Most noteably, since its creation, Shore’s algorithm has generated a great deal of discussion among the scientific community as it could be used to break the modern encryption keys. If a quantum computer was capable of efficiently using Shore’s algorithm, the use of encryption to secure bank accounts and other operations and the accompanying difficulty of mass numerical division, would cease to exist. Classic computers don’t handle these types of dificulties very well, so we can sleep peacefully without worrying that our bank account will be cleaned out by a quantum hacker. Another algorithm is Grover’s Algorithm, which was devised to sort through information in unordered data bases. Imagine searching through a phone book with a random assortment of names. In order to find a given telephone nukber you’d have to search through each and every listing, which would be cumbersom and time consuming. However, by applying grover’s algorithm to a quantum computer, you could retrieve the desired name in only a few seconds. But it should be noted that a single outcome is only a probable solution. The more times the comouter perfirms the calculations, the more liklley it is to find the proper solution ot the problem. Quantum computers are mainly designed to solve complex problems, which require us to deal with very large amounts of data. These types of machines will soon their practical application in research laboratories instead of computer games. The role of a quantum comoputer is to provide assistance in capturing what is beyond the boundry imposed by time and energy needs. Perhaps in the not so distant future we’ll be able to climb the ladder to a new rung of possibilities, like the creation of new drugs, breakthroughs in predicting the weather, and the development of new technological devices. We’re no longer caluclating on zeros and ones, but the problem of quantum comouters is percisely this reason. How do you program this thing? The way we do it today is with an MRI machine, we get a bunch of atoms, line them up, put them in a magnetic field, shoot electromagnetic radiation at it from an MRI machine, flip the charges and then measure the echo. That’s how we do it today. The problem is stability. Its difficult to build an program. It turnes out that interference, any kind of vibration will upset the vibrations of these atoms, creating nonsense, so that’s the fundamental problem, decohenerence. Decoherence is the reason why we cannot break codes with quantum computers. Why we dont have artificial intelligent machines as smart as the human brain. These atoms begin to decohere and begin to turn into a random jumble of atoms, just like the atoms in your body, making it useless. Wen will we have quantum computers, i dont know. But i think we’ll have molecular computers before we have quantum computers. That is, we’ll be able to compute on molecules. Nano-bio computing. Molecular transistors already exist, we can already make them, we ca make them out of graphene, which is one layer of carbon in a gigantic sheet. The world’s smallest molecular transistor is one carbon atom, that is the smallest molecular transistor we’ve been able to make so far. I’ll bet molecular computers replace silicon power before quantum computers.