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arXiv quant-ph/9807005quant-ph
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关于(自旋)相干态路径积分的注记

A Note on (Spin-) Coherent-State Path Integral

Junya Shibata, Shin Takagi

摘要:

指出了常用的自旋相干态路径积分的连续时间形式存在着一些根本性的困难。它们已经出现在单自旋系统中,并且在“经典作用”的水平上,更不用说围绕“经典路径”的波动了。在(玻色子-)相干态路径积分的情况下也存在类似的困难;虽然在“经典水平”上可以用巧妙的技巧(Klauder的$ε$ -处方)部分地规避,但它们在涨落水平上表现出来。对这些困难的起源的详细分析清楚地表明,避免它们的唯一方法是使用适当的离散时间形式主义。论文明确说明了一个谐振子和自旋下的恒定磁场。

英文摘要:

It is pointed out that there are some fundamental difficulties with the frequently used continuous-time formalism of the spin-coherent-state path integral. They arise already in a single-spin system and at the level of the "classical action" not to speak of fluctuations around the "classical path". Similar difficulties turn out to be present in the case of the (boson-)coherent-state path integral as well; although partially circumventable by an ingenious trick (Klauder's $ε$-prescription) at the "classical level", they manifest themselves at the level of fluctuations. Detailed analysis of the origin of these difficulties makes it clear that the only way of avoiding them is to work with the proper discrete-time formalism. The thesis is explicitly illustrated with a harmonic oscillator and a spin under a constant magnetic field.

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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