Ok, this is an article explaining quantum computing and it’s benefits to humanity in the future.
So you might be asking the questions “ What exactly does quantum physics have to do with computers? How does quantum computing work and how is a quantum computer different from a conventional semiconductor based computer?”
A quantum computer by design is a computer based on the principles of quantum physics and is able to do computational work at a power for above that of a traditional computer. Up till now quantum computers have been constructed on small scales and work is being continuously done to upscale them to more practical designs.
How Conventional Computers Work
Your conventional computers work by storing data in binary (a series of 0s&1s i.e. On and Offs) format, helped by the switching of transistors. A single unit of computer memory is called a bit and the computation is the manipulation of these bits in different algorithms to do complex, real life tasks, based on Boolean Logic.
How a Quantum Computer Would Work
A quantum computer has 4 states, instead of the regular two, the 1&0. The two additional states are the quantum superposition of 1 & 0 states. Such a bit is called qubit (quantum bit) and allows for far more flexibility than binary system.
A quantum computer has abilities far greater than present day conventional computers and will be able to perform calculation an order of magnitude more. Some people have fear that our modern encryption and cryptography standards won’t be able to withstand the raw computation and brute force power of quantum computers and the financial world would be hurt by the quantum computers ripping apart security encryption. Quantum computing would be able to factor large numbers that would take traditional computers even greater time than the lifespan of universe. A quantum computer can do that in a reasonable amount of time.
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To understand why quantum computing is very fast, consider this. A qubit is made from a superposition of the 1 state and the 0 state and it performs calculation with another qubit in similar superposition. One calculation can actually produce 4 results a 1/0 result, a 0/1 result, a 1/1 result and a 0/0 result. This ability of quantum computers to perform simultaneous computations parallel is called quantum parallelism.
The exact physical principal behind the working of quantum computing is theoretically complex. Generally, the concept is explained using the many-world interpretation of quantum physics, through which the computer performs calculation in many universes simultaneously. The qubits are in state of ‘quantum decoherence’. This whole thing might seem far-fetched but has actually been used to predict experimental results.
The History of Quantum Computing
Quantum computing can trace back its roots to a 1959 speech by the great physicist Richard P. Feynman in which he described the effects of miniaturization and also presenting the idea of exploiting quantum effects in creation of more powerful computers.
This was of course too early a time for development of quantum computers, as even traditional computers had not been developed far enough and were real challenge for engineers and scientists. That is the reason for many years of neglect or disinterest in this regard of making Feynman’s predictions true.
In 1985, the idea of “quantum logic gates” was proposed by David Deutsch, a professor of University of Oxford’s, as a way of utilizing the quantum realm inside a computer. Deutch’s paper had shown that any physical process can be modeled by a quantum computer.
In 1994, AT&T’s Peter Shor put forward an algorithm that utilized only 6 qubits to perform some basic factorizations .
A few quantum computers have been built. The first was a 2-qubit quantum computer in 1998 which could perform simple calculations before losing decoherence after a few nanoseconds. In 2000, some teams fruitfully built both a 4-qubit and a 7-qubit quantum computer. The most popular of the lot is the D-Wave set of quantum computers which have been built by the Canadian company. These quantum computers have been bought by mega firms like Google, NASA and Lockheed Martin, confirming that quantum computers have a place among the top of the lot computers and the industry is trying to bring them forward. Research on the subject is still very active.
Difficulties with Quantum Computers
The quantum computer’s strength of quantum decoherence is its main drawback as well. The qubit calculations performed while quantum wave function Is in superposition is the main drawback as well. Measurement of any type made to a quantum computer leads to breaking down of decoherence and wave function then collapses into a single state instead of a super positioned qubit which is one and off at the same time.
The physical requirements for quantum computing on such a system on large scale is difficult and will require significant advancements in nanotechnology, superconductors and such. But there is hope, as D-Wave has shown and while its computers might be shrouded in mystery and controversy as to if they are real quantum computers or not, but the future holds bright promise.