论文标题
磁场中旋转的量子兰格文方程：分析
Quantum Langevin Equation of a spin in a magnetic field : an analysis
论文作者
论文摘要
我们在存在磁场的情况下为量子自旋得出量子兰格文素方程，并使用欧姆浴模型研究了马尔可夫极限的动力学。我们将分析扩展到有限的记忆力。我们研究磁矩期望值的时间演变。自旋自动相关函数表现出阻尼的振荡行为，随机时间由阻尼速率确定以及DRUDE浴模型的记忆时间。我们还分析了欧姆浴模型系统的自旋响应函数。我们的结果与冷原子实验中的发现一致。此外，我们做出预测，可以在将来的超冷原子实验中进行测试。
We derive a quantum Langevin equation for a quantum spin in the presence of a magnetic field and study its dynamics in the Markovian limit using the Ohmic bath model. We extend our analysis to the Drude bath with a finite memory. We study the time evolution of the expectation values of the magnetic moments. The spin auto-correlation functions exhibit a damped oscillatory behaviour with the randomization time being determined by the damping rate and also the memory time for the Drude bath model. We also analyse the spin response function of the system for the Ohmic bath model. Our results are consistent with findings in cold atom experiments. In addition we make predictions which can be tested in future ultra cold atom experiments.
