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arXiv quant-ph/0312217quant-ph
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某些耦合自旋模型的演化速度

Evolution speed in some coupled-spin models

R. F. Sawyer

摘要:

我们调查的时间演化的一些模型与N自旋和成对耦合,对于大N的情况下,为了比较演化时间与“速度极限”的最小值在文献中得出。无论是在一个(对称)的情况下,每对之间的耦合强度相同,并在对称性破缺的情况下,演变到一个状态,其中最简单的初始状态已经演变成一个几乎正交的状态所需的时间是成比例的1/N,是速度限制的时间。然而,对称性破缺情况下的系数更接近速度极限值。引入一个不同的标准的进化速度,在占领的宏观变化的基础上,我们发现一个相应的增强率在不对称的情况下相比,对称的情况下。

英文摘要:

We investigate the time evolution of some models with N spins and pairwise couplings, for the case of large N, in order to compare evolution times with "speed limit" minima derived in the literature. Both in a (symmetric) case with couplings of the same strength between each pair and in a case of broken symmetry, the times necessary for evolution to a state in which the simplest initial state has evolved into a nearly orthogonal state are proportional to 1/N, as is the speed limit time. However the coefficient in the broken symmetry case comes much closer to the speed limit value. Introducing a different criterion for evolution speed, based on macroscopic changes in occupation, we find a corresponding enhancement in rates in the asymmetric case as compared to the symmetric case.

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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