Yunnan Daxue xuebao. Shehui kexue ban
Quantum gates based on the geometric and topologic phases
Yu-Mei Gao, Hu Lian
Abstract
This article summarizes the recent results about geometric and topologic quantum computation.Based on a rigorous theorem concerned on orthogonal superposition quantum state proved in this paper,an orthogonal state method is proposed to carry out the non-adiabatic geometric quantum computation.And these geometric quantum gates are demonstrated in detail by two two-level systems: one is the system of spin-1/2 particle under NMR uniform rotating magnetic field;the other is asymmetric nano-SQUID circuit.The paper presents a perfect explanation for the early controversial helical fiber experiment done by Chiao R.Y.,also proposes a scheme of constructing topologic gates and illustrates these gates still with above two two-level systems.Finally,a brief comment is given on the controllability of quantum gates with the asymmetric nano-SQUID circuit.