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arXiv 1206.0797quant-ph
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Dicke模型的泛临界行为

Universal Critical Behavior in the Dicke Model

Octavio Castaños, Eduardo Nahmad-Achar, Ramón López-Peña, Jorge G. Hirsch

摘要:

利用半经典解和精确解确定了有限个原子的原子-场耦合强度的临界值。在半经典方法中,我们使用的变分程序与相干态和自适应态,而精确的量子解的保真度的概念。这些程序允许在模型中的相变的确定,并符合热力学极限。对于上述三种情况,作为原子-场耦合参数的隐函数,得到了适用于基态和第一激发态的电磁场第一积分和原子相对布居的期望值的普适参数曲线。

英文摘要:

The critical value of the atom-field coupling strength for a finite number of atoms is deter- mined by means of both, semiclassical and exact solutions. In the semiclassical approach we use a variational procedure with coherent and symmetry-adapted states, while for the exact quantum solution the concept of fidelity is employed. These procedures allow for the determination of the phase transitions in the model, and coincide in the thermodynamic limit. For the three cases men- tioned above, universal parametric curves are obtained for the expectation values of both the first quadrature of the electromagnetic field, and the atomic relative population, as implicit functions of the atom-field coupling parameter, valid for the ground- and first-excited states.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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