Decoherence Time of the Coupled-Dot Quantum Bit

• Main Authors: Da-Ching Cho, 邱大秦
• Other Authors: George Yu-Shu Wu
• Format: Others
• Language: en_US
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/87459160910222378072

碩士 === 國立清華大學 === 電子工程研究所 === 91 === Abstract The decoherence time of the coupled-dot quantum bit is studied. The dissipative mechanisms we consider are not only the effect from the phonon field but also that from the higher energy level due to the asymmetrical configuration. Influence functional has been used to eliminate the uninterested infinite oscillators’ degrees of freedom and the cross terms involved with the interference effect of the two different coupling frequencies are derived naturally from the nine-state path. Besides, the reasonable formula for evaluating effective decay rate is derived when the cross terms are neglected, and the phonon-dressing effect is also included to affect the performance of suchlike devices.