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arXiv 2308.01351cond-mat.dis-nngr-qc
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负曲率曲面上弱局域化的缺失

Absence of Weak Localization on Negative Curvature Surfaces

Jonathan B. Curtis, Prineha Narang, Victor Galitski

AI总结:

该研究提出负曲率流形可通过增加粒子相干轨迹数量、提供自返回路径红外截断破坏弱局域化,在双曲空间计算Cooperon验证了无碰撞下的经典扩散恢复,为二维无序体系局域化抑制提供了曲率调控的新机制。

摘要:

无序与量子干涉的相互作用会催生种类繁多的物理现象,其中就包括著名的Anderson局域化(安德森局域化)——即不同粒子轨迹间的量子干涉导致扩散输运完全消失。在二维体系中,人们普遍认为只要存在无序,在足够大的长度尺度下所有态都会发生局域化,不过如果能带具有拓扑性质或是存在强自旋轨道耦合,这种局域化过程可能会被抑制。在本短文中,我们提出了一个简洁的论证,给出了另一种破坏局域化的机制:通过调控扩散发生所在流形的基础曲率。我们证明,负曲率流形对自返回路径的概率存在天然的红外截断。我们在双曲空间中对Cooperon(库珀子,与电导率的弱局域化修正直接相关)进行了显式计算。结果表明,恒定负曲率会导致粒子在给定时间内能够相干遍历的可用轨迹数量快速增长,从而降低干涉效应的重要性,即便在没有非弹性碰撞的情况下也能恢复经典扩散行为。我们最后提出,这一结果有望通过量子模拟器开展实验验证。

英文摘要:

The interplay between disorder and quantum interference leads to a wide variety of physical phenomena including celebrated Anderson localization -- the complete absence of diffusive transport due to quantum interference between different particle trajectories. In two dimensions, any amount of disorder is thought to induce localization of all states at long enough length scales, though this may be prevented if bands are topological or have strong spin-orbit coupling. In this note, we present a simple argument providing another mechanism for disrupting localization: by tuning the underlying curvature of the manifold on which diffusion takes place. We show that negative curvature manifolds contain a natural infrared cut off for the probability of self returning paths. We provide explicit calculations of the Cooperon -- directly related to the weak-localization corrections to the conductivity -- in hyperbolic space. It is shown that constant negative curvature leads to a rapid growth in the number of available trajectories a particle can coherently traverse in a given time, reducing the importance of interference effects and restoring classical diffusive behavior even in the absence of inelastic collisions. We conclude by arguing that this result may be amenable to experimental verification through the use of quantum simulators.

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