电磁场与二能级原子相互作用的量子相干性

Quantum Coherence of Interaction Between Two-level Atom and Electromagnetic Field

通过密度矩阵方法讨论了处于特定环境下二能级原子的量子相干性.采用原子算符来表示经典电磁场中二能级原子的哈密顿算符;根据薛定谔方程,导出了二能级原子系统密度矩阵的演化方程;通过求解此演化方程,得到这个系统的密度矩阵具体形式.并由此得出此纯态系统具有良好的相干保持特性.

Quantum coherence of two-level atom in a certain circumstance is discused by the method of density matrix. Hamitonian operator of two-level atom in classic electromagnetic field is expressed by atomic operators; based on Schodinger equation,the evolution equations of density matrix in two-level atomic system is gained; by solving the evolution equations, the detailed density matrix in such a system is derived. It is obtained that the pure state system can retain nicer quantum coherence.