New Method for Increasing Calculations Capacity and Speed of Today Computers Using Spin States as Quantum Bits

Iranian researchers at Shiraz University introduced a new method for increasing calculations capacity and speed of today computers using spin states as quantum bits.

Today, the researches on changing computers from conventional to quantum situation in which the capacity of calculations and speed is higher have been developed significantly. One of the candidate proposals for the materialization of the idea is using spin states as quantum bits.

"This research has been conducted with the aim of analyzing electron spin precession around magnetic field of a unidirectional ring as well as Rashba effect. Electrons spin precession around magnetic field, whether classic or quantum, has been studied since long time ago and forms a foundation for MRI. On the other hand, spin behavior as a quantum bit is used for quantum processing of information," Mohammad Mehdi Golshan, an Iranian physicist, said to the news service of INIC.

"Since a phenomenon called Rashba effect appears in nanostructures made of different semiconductors (such as unidirectional ring), examining the effects of this phenomenon on spin states for relevant cases in MRI is of great importance", Golshan mentioned.

He first wrote the Hamiltonian of an electron exposed to external magnetic field, Rashba effect and ring spatial limitation included, then derived time evolution operator. The average spin components time evolution was calculated together with sublayers.

"Then we came to this conclusion that electron spin precession in different points of ring is different and sublayers behavior depends on electrons position," the faculty member of Shiraz University said.

The present research has two main advantages over recent ones. First, Rashba effect was included completely. Second, spatial limitations effects (the ring itself brings about spatial limitations) were considered completely in the configuration.

The details of the present study are available at Journal of Computational and Theoretical Nanoscience, volume 6, pages 1519 to1522, 2009.