Quantum Computer Inside A Diamond - Researchers' Eureka Moment!

Quantum computing has been a subject of research for a long time, but a team of scientists from USC (University Of Southern California) has gone a step ahead and they are ready with a demo of working Quantum computer. The computer is the first of its kind to provide protection against decoherence. Decoherence is the noise due to which computers can’t function properly. Current quantum computers, though small in size, cannot compete with big traditional computers in terms of speed, but this demonstration shows the future as these computers can be scaled up easily to provide faster computation.

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The multinational team including Professor Daniel Lidar, University of Southern California (USC), Zhihui wang, postdoctoral researcher at USC, researchers from University of Technology in Netherlands, Iowa State University and University of California, Santa Barbara published their research in #-Link-Snipped-#. The team used two quantum bits, called “qubits”, which are made of subatomic particles. The benefit of using qubits over traditional computer bits is that they have a property called superposition using which they can encode two bits at same time. While in traditional computers, bits can be stored one at a time, its either one or zero. Superposition, included with the ability of quatum states to “tunnel” through energy barriers can make quantum computers more optimized and faster than traditional computers.

Diamonds with impurities are normally not that attractive when used in jewelry. The team used these impurities for their benefit. They used nitrogen nuclei as the first qubit and an electron as second qubit. To be precise, the spin of these sub atomic particles was used as qubit. Electrons are smaller and faster in computation than nuclei, but the problem with them is that they are more vulnerable to decoherence. A nucleus is large and stable but slower. According to Professor Daniel, decoherence time of a nucleus is in milliseconds, which is quite long. This is the first time someone has tossed the idea of protection against decoherence in solid state computing by using microwave pulses to continually switch the direction of the electron spin rotation. Switching the direction of rotation time reverses the inconsistencies in motion as the qubits move back to their original position which produce an effect like time travel.

In the demonstration,  the team showed how closely their computer’s working matched Grover’s algorithm. The algorithm was developed by Lov Grover of Bell Labs in 1996. The procedure is to search a name in an unsorted phone book when you have only been given the phone number. Now, in the traditional computers, on an average, we normally find the name in half of the tries. But with quantum computer you can find the result much more quickly. Researches have shown that quantum computers can find the result in the very first search, every time. The team’s computer was able to find the result in first try about 95 percent of the time, showing that it works by following quantum computing rules. The complete research paper can be read #-Link-Snipped-#.