Abstract

Two-level systems, such as atoms or spins, are considered as a fascinating quantum information carrier-qubit in quantum computing. For the operation of computing, the geometric manipulation of two-level atoms on the Bloch sphere is one of the most attractive way since the resultant phase solely depends on the amount of the solid angle enclosed by a cyclic evolution path. In 2004, Tian et al proposed a scheme for universal single qubit operations on two-level atoms which was composed purely by laser-controlled geometric phase changes and demonstrated the first primitive laser-pulse-controlled Bloch vector operation using Tm-ion doped in a crystal by photon echo process [1].

© 2007 IEEE