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arXiv 2205.09486cond-mat.dis-nn
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具有相对相位的Aubry-André-Harper模型的精确迁移率边

Exact mobility edges in Aubry-André-Harper models with relative phases

Xiaoming Cai, Yi-Cong Yu

摘要:

迁移率边是局域化物理中的一个核心概念,它是在光谱中区分局域态和扩展态的一个临界能量。然而,很少有模型具有精确的ME。本文推广了[Phys. Rev. Lett. 114,146601(2015)],并且最近在[Phys. Rev. Lett. 126,040603(2021)],通过在准周期势中引入相对相位。应用Avila的整体理论,我们解析计算所有单粒子态的局域化长度,并确定ME的精确表达式,这两者都显着依赖于相对相位。通过数值模拟验证了它们,并提供了精确表达式的物理感知。我们进一步证明了ME的精确表达式适用于更广泛的广义Aubry-André-Harper模型。此外,我们表明,确切的ME是相关的对偶模型,其中有长程跳跃。

英文摘要:

Mobility edge (ME), a critical energy separating localized and extended states in spectrum, is a central concept in understanding the localization physics. However, there are few models with exact MEs. In the paper, we generalize the Aubry-André-Harper model proposed in [Phys. Rev. Lett. 114, 146601 (2015)] and recently realized in [Phys. Rev. Lett. 126, 040603 (2021)], by introducing a relative phase in the quasiperiodic potential. Applying Avila's global theory we analytically compute localization lengths of all single-particle states and determine the exact expression of ME, which both significantly depend on the relative phase. They are verified by numerical simulations, and a physical perception of the exact expression is also provided. We further demonstrate that the exact expression of ME works for an even broad class of generalized Aubry-André-Harper models. Moreover, we show that the exact ME is related to the one in the dual model which has long-range hoppings.

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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