Emergent Hall phases at quantum phase transitions with accompanying changes in Fermi surface topology
Emergent Hall phases at quantum phase transitions with accompanying changes in Fermi surface topology
复制标题
量子相变时的突现霍尔相以及费米表面拓扑的伴随变化
DOI：
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
A. Taraphder
中科院分区：
文献类型：
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作者：
N. Mohanta;S. Bandopadhyay;S. Lal;A. Taraphder
竞争秩序，如超导性和铁磁性，对费米液体的影响已经得到了很好的证实。一个全面的理解，这样的竞争，在金属的费米面有一个非平凡的拓扑结构尚未实现。在这里，我们在一个原型系统中解决这个问题：2D Rashba半金属。我们发现，主导的超导性与Rashba自旋轨道相互作用（SOI）相互作用，形成了具有Bogoliubov-de Gennes（BdG）准粒子无带隙边缘态的新型本征异常霍尔效应（AHE）。在巡回铁磁体的情况下，内禀AHE产生的Berry曲率效应的能带结构。这种现象是强大的，即使次主导铁磁性显着改变配对对称性的性质。一个新兴的自旋霍尔相位涉及费米表面拓扑结构的变化，发现伴随着这种Lifshitz量子相变。我们证明了共存的原始和新颖的AHE在弱无序的存在。我们提供了一个比较我们的结果与实验上的二维电子气在氧化物异质界面，以及作出一些可检验的预测。
The effects of competing orders, such as superconductivity and ferromagnetism, on a Fermi liquid are well established. A comprehensive understanding of such a competition in a metal whose Fermi surface has a non-trivial topology is yet to be achieved. Here, we address this question in a prototypical system: the 2D Rashba semimetal. We show that dominant superconductivity interplays with Rashba spin orbit interactions (SOI) in forming a novel intrinsic anomalous Hall effect (AHE) with gapless edge states of Bogoliubov-de Gennes (BdG) quasiparticles. As in the case of itinerant ferromagnets, the intrinsic AHE arises from Berry curvature effects in the band structure. This phenomenon is robust even as sub-dominant ferromagnetism dramatically changes the nature of pairing symmetry. An emergent spin Hall phase involving a change in Fermi-surface topology is found to accompany this Lifshitz quantum phase transition. We demonstrate the coexistence of the original and novel AHE in the presence of weak disorder. We offer a comparison of our results with experiments on the two dimensional electron gas at oxide hetero-interfaces as well as make some testable predictions.