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arXiv quant-ph/0510024quant-ph
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绝热近似的一种新微扰方法

A new perturbative approach to the adiabatic approximation

R. MacKenzie, E. Marcotte, H. Paquette

摘要:

提出了一种新的、直观的微扰方法来求解含时量子力学问题,这种方法在哈密顿量演化缓慢的情况下是有用的。一个系统的状态开始于初始哈密顿量的瞬时本征态,它被写为一个幂级数,具有一个简单的图形表示。该系列的每一项对应于一个序列的“绝热”演变,在此期间,系统保持在一个瞬时本征态的哈密顿量,间断的过渡从一个状态到另一个。这个级数的第一项是标准绝热演化,下一项是众所周知的第一次修正,随后的各项基本上可以通过检查写下来。虽然最后的结果也许并不令人惊讶,但它似乎并不广为人知,据我们所知,解释是新的。给出了该方法在绝热近似中的应用,并讨论了这种近似的有效性。

英文摘要:

A new and intuitive perturbative approach to time-dependent quantum mechanics problems is presented, which is useful in situations where the evolution of the Hamiltonian is slow. The state of a system which starts in an instantaneous eigenstate of the initial Hamiltonian is written as a power series which has a straightforward diagrammatic representation. Each term of the series corresponds to a sequence of "adiabatic" evolutions, during which the system remains in an instantaneous eigenstate of the Hamiltonian, punctuated by transitions from one state to another. The first term of this series is the standard adiabatic evolution, the next is the well-known first correction to it, and subsequent terms can be written down essentially by inspection. Although the final result is perhaps not terribly surprising, it seems to be not widely known, and the interpretation is new, as far as we know. Application of the method to the adiabatic approximation is given, and some discussion of the validity of this approximation is presented.

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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