Tokyo, Japan, September 16, 2004--Nippon Telegraph and Telephone (NTT) in collaboration with the Japan Science and Technology Agency (JST) have succeeded in flipping the supercurrent flow (quantum state transition) in one-, two-, and three-photon absorption processes by irradiating a superconducting flux qubit with resonant microwave photons.

"We have confirmed that quantum mechanics, which is usually applied to microscopic objects such as elementary particles and atoms, can also be applied to the macroscopic state (consisting of millions of Cooper pairs) in a superconducting flux qubit of six micrometers in size," according to Hideaki Takayanagi of the NTT Basic Research Laboratories, who presented the results during the Japan Physical Society meeting at Aomori University on September 13. "The qubit is composed of three Josephson junctions of sub-micrometer scale and obeys the laws of quantum mechanics. It has proved to be a promising candidate as a quantum computer building block. We now plan to extend the coherence time of a qubit and this will take us one step closer to realizing a quantum computer."

Thu Sep 16 00:01:00 CDT 2004