Approximate master equations for atom optics.
Approximate master equations for atom optics.
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原子光学的近似主方程。
DOI：
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发表时间：
2002
期刊：
影响因子：
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通讯作者：
P. Warszawski
中科院分区：
文献类型：
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作者：
D. Atkins;H. Wiseman;P. Warszawski
在原子光学领域，许多实验的基础是二能级原子与光场的耦合。这个系统的演化是由一个主方程控制的。这个主方程的不可逆分量描述了光子从原子的自发辐射。对于许多应用，有必要将这种不可逆演变的影响降至最低。这可以通过具有远失谐光场来实现。这种机制的缺点是，使失谐非常大使得求解主方程所需的时间步长非常小，比任何显著演化的时间尺度小得多。这使得问题在数值上非常密集。由于这个原因，近似被用来模拟主方程，这是更容易解决的数值。本文分析了四种近似：标准绝热近似、更复杂的绝热近似（以前没有使用过）、久期近似和全量子修饰态近似。每一个的优点和缺点进行了调查方面的准确性，复杂性和所需的资源来模拟。在一个特别实验感兴趣的参数制度，只有复杂的绝热和dressed状态近似同意与确切的演变。
In the field of atom optics, the basis of many experiments is a two-level atom coupled to a light field. The evolution of this system is governed by a master equation. The irreversible components of this master equation describe the spontaneous emission of photons from the atom. For many applications, it is necessary to minimize the effect of this irreversible evolution. This can be achieved by having a far detuned light field. The drawback of this regime is that making the detuning very large makes the time step required to solve the master equation very small, much smaller than the time scale of any significant evolution. This makes the problem very numerically intensive. For this reason, approximations are used to simulate the master equation, which are more numerically tractable to solve. This paper analyzes four approximations: The standard adiabatic approximation, a more sophisticated adiabatic approximation (not used before), a secular approximation, and a fully quantum dressed-state approximation. The advantages and disadvantages of each are investigated with respect to accuracy, complexity, and the resources required to simulate. In a parameter regime of particular experimental interest, only the sophisticated adiabatic and dressed-state approximations agree well with the exact evolution.