中国科学G辑(英文版)
中國科學G輯(英文版)
중국과학G집(영문판)
SCIENCE IN CHINA (PHYSICS ASTRONOMY)
2003年
6期
580-588
,共9页
李勇%易俗%尤力%孙昌璞
李勇%易俗%尤力%孫昌璞
리용%역속%우력%손창박
quantum memory%atomic ensemble%qubit%quantum leakage
We generalize the conception of quantum leakage for the atomic collective excitation states. By making use of the atomic coherence state approach, we study the influence of the atomic spatial motion on the symmetric collective states of 2-level atomic ensemble due to inhomogeneous coupling. In the macroscopic limit, we analyze the quantum decoherence of the collective atomic state by calculating the quantum leakage for a very large ensemble at a finite temperature. Our investigations show that the fidelity of the atomic system will not be good in the case of atom number N →∞. Therefore, quantum leakage is an inevitable problem in using the atomic ensemble as a quantum information memory. The detailed calculations shed theoretical light on quantum processing using atomic ensemble collective qubit.
