Monday, February 14, 2011

Advantages Of Quantum Computing Over Traditional Approaches

Since the introduction of Quantum Computing in 1982 by Richard Feynmen (Bone & Castro, 2006) the technological developments over this past generation have been monumental, from a simple algorithm to teleportation. This has had an adverse effect on classical computing by discovering the power of Quantum computing and its immense abilities. Unfortunately there is not a commercially available Quantum computer yet, as today’s computers still greatly overpower the current fastest Quantum computer which is 28 qubits.  Now what does a qubit have to do with the speed of a computer?


As you know a classic computer works in bits so it’s either a one or a zero, a Quantum computer works in Quantum bits or qubits  this can be a one or a zero or both this is called superposition and is the basics of Quantum mechanics and therefore theoretically the qubit can hold an infinite amount of information. According to Nagy(2007) superposition suggest that while we do not know the state of an object it is actually in all possible states at the same time. When we come to measure a qubit we calculate the probability of the qubit being either a one or a zero this then brings the qubit out of the superposition and this only happens when we measure it. A good example of this is the double slit experiment. This was carried out in the 1800s by a physicist called Thomas Young. He passed light or electrons through two slits in a barrier. The results were that the light made an interference pattern which is usually made by waves not particles instead of two bands of light. To investigate Young observed or measured to see what was happening when the light hit the slits, when he did this the light behaved in the way it should have, by making two bands of light rather than the interference pattern (Jones,2004). Once the qubit has been measured it then collapses out of the superposition this then makes remaining measurements unreliable or completely useless.


Now we know the physics of a Quantum computer, building one is a whole new problem. For a qubit to maintain its superposition it needs to be isolated as it cannot interact with other objects. There are a number of ways to build a Quantum computer the simplest is to trap an atom in a buckyball, which is a sphere formed of 60 carbon atoms, and use its electrons as a qubit. This only kept the qubit in the superposition for only 500 nanoseconds but this is nowhere near long enough to perform a calculation. To combat this problem a Team at Hitachi developed a way to use existing silicon chips in Quantum computers by using Quantum dots. These dots act as qubits on the surface and can be made into large scale computers (Ecomonist, 2006). These methods have been tried and tested and have proved inadequate, recently a company called D-Wave built the current fastest computer of 28 qubits using a technology called adiabatic quantum computing. Rose (2009) state that AQC uses superconducting metals instead of semiconductors at a very low temperature and in a magnetic vacuum.


Now we know basically how a Quantum computer works I will now discuss the advantages of a Quantum computer over the ones we use today. The most obvious benefit of Quantum computing is the processing power. Although today’s computers are still a lot faster than the current fastest Quantum computer but the theoretical power is enormous. The reason this is possible is there is no limit of the size of the instructions.  Classical computers use either 32 bit instructions or 64 bit but with a Quantum computer there isn’t a limit thanks to the qubit. In a classical computer transistors are used to express ones and zeros, so to express the number 256 you need 8 bits were with Quantum computing a qubit can hold that and much more. This inherently removes the need to read from memory locations this makes the retrieval of data almost instantaneous. Another great benefit of Quantum computing is Entanglement. This is the ability of a Quantum link where if one particle changes the other particles do to without any physical connection. This would then enable computers to communicate over long distances with virtually no lag and the dramatic reduce in cost.
                
With this great processing power Artificial Intelligence will greatly benefit as currently the algorithms currently used are extremely complex and cannot be processed fast enough. With this increase in processing power AI will be able to reach its true potential,  theoretically it could contain more processing power than a human brain making true AI possible (Dunn, 2005) .
               
Another advantage is the benefit of Quantum Cryptography. Quantum cryptography is used today but it still has issues. Its use within a Quantum computer would make all communications almost completely secure. The way Quantum cryptography works is by using photons which are tiny packets of light. A photon has four possible polarised states (|), (- -), (/) or (). internet more secure especially when paying for items over the internet.  Also if data got lost or stolen it would be very hard to gain access to the data making things like identify theft a thing of the past.
                
Probably the most outstanding advantage of Quantum computing is teleportation. Teleportation is the ability to make an object or a person completely disintegrate while a perfect replica appears in another place. Not many physicists have taken the theory of teleportation seriously but with the introduction of Quantum computing this has now become a reality. A group of scientists discovered a way to make a perfect replica of an object using a feature of Quantum mechanics called EPR or Einstein-Podolsky-Rosen effect and also Entanglement. To achieve this they partially scanned an original object, object A and passed the remaining information to Object C using the EPR effect. Once object C had the information a treatment was applied to it then object C was manipulated to the same stage object A was before it was scanned. A and C have never been in contact with each other and since A is not in its original state from being disturbed by the scanning and C is in the exactly the same state A was original in, therefore this is classed as teleportation not replication.  If we could get the information from each atom everything in your bedroom, office and including you could be teleported to a difference place and everything instantly appear in front of you. Unfortunately teleporting a human being requires tremendous amounts of information and the constant changing state of mind of a human makes teleportation on a major scale science fiction for the foreseeable future but with the rapid advancements in Quantum computing there is a theoretical basis for teleportation. Below is a diagram of the describe process of teleportation (Chen, 2005).


                   Source: http://www.research.ibm.com/quantuminfo/teleportation/

Teleportation benefits Quantum computing too, one of the major benefits is the networking of Quantum computers. Information will be transferred instantaneously between computers making communications like video conferencing real time. Another great advantage is the use of teleportation in the inner workings of a Quantum computer this will reduce errors with and more resilient to processing errors and brings down the percentage of errors to just 1%.  This will then directly benefit the building of Quantum computers and there will less parts needed and reducing costs (Smalley, 2004). This could in the future make Quantum computers on the same price scale as today’s computers. Users will experience a great reduction in errors, so computer freezes and blue screen of death could become a thing of the past.
               
                Quantum computing brings some great advantages and incredible benefits and will change the way we will use a computer forever but as with most technological advances there are problems. You would think that the major problem would be we don’t have the technology yet or we can’t accommodate more than a certain amount of qubits, your right but they are not the major problem s facing Quantum computing it’s what many physicists fear Singularity.


Singularity is a hypothesis in futurology in which technology e.g. computers will become more intelligent than humans and could wipe out the human race, the reason for its names is that it will only happen once. In this the last decade it has become more prominent especially with Quantum computing developing at such a fast rate. Many scientists believe that it will happen by the year 2030 (Vinge, 1993) and Quantum computing has contributed to this greatly. One of the most likely advances which will make Singularity happen is true AI, when a machine can be “awake” and be classed as superhumanly intelligent. As discussed in the advantages of Quantum computing, it greatly benefits AI from it sheer processing power. This is in the process of becoming a reality,as a scientist by the name of Hugo de Garis is currently developing the first artificial brain in China. He believes in the next few decades these artificial brains will be one of the largest industries and that millions if not billions of people will invest in a robot for their home that will be intelligent and useful(Garis,  2009). Garis (2009) also states that each of the robots will be upgraded every two to three years and will be more intelligent therefore making the gap between human and machine intelligence smaller. If this ever does become possible and superhumanly intelligent machines are created they themselves will create even more intelligent machines eventually becoming more intelligent that humans. Now would you want of them in your home? There are ways in which we can prevent this from happening, one of the most easiest and effect ways is to place a limit of machine intelligence power. We could limit their power to that just below of humans this would then stop machines from developing better versions of themselves and becoming more intelligent(Eder, 1994). Another very simple but effect solution is to programme safety measures into machines using the laws of robotics  by Isaac Asimov, so if or when they become these super intelligent machines we are protected. The problem with this is if they become that intelligent wont they be able to find a way around these rules. Another factor that might prevent Singularity is Moores Law. According to Moores law the transistors of a circuit board doubled every year but today we say it’s every 18 months at the moment transistors are being manufactured in nanometers and we are not too sure how long this can continue. If we reach the physical limit before we can create superhumanly intelligent machines this itself could prevent Singularity, hopefully. (Strickland, 2007).


One of the other major problems facing Quantum computing is collaboration with classical computers. When Quantum computers become commercial available not all business will be able to afford or want to adopt the technology and this will cause a massive upset in the IT industry. This then presents the problem of the two very different technologies being able to communicate with each other. As we know classical computers send information and communicate using bits either being a one or a zero,  we currently measure qubits in the same way but brings the problem on collapsing the qubit out of its super position. If the two could communicate this would greatly affect the performance of the Quantum computer as to communicate would cause the qubits to become more or less normal bits. Also the technology used in the two computers are very different, a classical computer uses transistors in its processor were a Quantum computer uses photon or ions. It would be near impossible for them to communicate without some sort of converter or interpreter to enabling the two different technologies to talk, but even building this converter will be extremely problematic itself. Scientists have seemed to ignore this problem and concentrate on developing the Quantum computer further and I have not found any evidence of attempting to communicate a Quantum computer and a classical. If we continue to ignore this problem when Quantum computers do become available business will be apprehensive to adopt the technology and Quantum computers could only be around for a short time then phased out.


Another problem relating to businesses is the cost of implementing Quantum architecture. At the moment the cost of building a Quantum computer is extremely high as the needed for the qubits to be completed isolated and superconducting metals to control the heat which is generated. NASA built the current Quantum chip for D-Waves 28 qubit computer and use superconducting metals that are used in modern space shuttles (Ames, 2007) and the cost of the metals and the process used to make them superconducting is very expensive. Quantum computers are still relatively large compared to classical computers and use a massive amount of electricity to power itself and for the huge amount of cooling needed. Until the advances in Quantum technology are made it will be extremely costly to use and will not be feasible enough for even research labs to use.

         
Overall Quantum computing brings about some great advantages, immense processing power and teleportation but also some very real problems such as the fear of singularity. Quantum computing has many advantages over the traditional approaches with the power of the qubit over the normal bit and the security of Quantum cryptography but this will only be a reality if we can continue to develop the technology and to be able to compete with the computers of today.  I feel that at this current moment with Quantum in its early development stage it will not provide any great benefits for the next couple of decades. The demand for Quantum computing currently isn’t very high but we are just coming to the physical limit of microprocessor as they can’t get much smaller, although sciences will greatly benefit, as DNA sequencing will become less expensive with the introduction of Quantum computing (Sci-Tech, 2009).


Quantum computing is developing at an enormous rate especially over this past decade with D- Wave making a working Quantum computer and the Advanced Research and Development Activity agency say by 2012 they will have an experimental 50 qubit computer (Ketchersid, 2007). So maybe the use of Quantum computers in our homes isn’t that far away. Maybe sometime in the distant future computers will be the size of an atom know as nano computers which will bring self replicating abilities and be able to repair humans by rebuilding them (Murch, 2004). Imagine that? 

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