Nernst effect of the dice lattice in a strong magnetic field

IF 2.9 3区物理与天体物理 Q3 NANOSCIENCE & NANOTECHNOLOGY

Physica E-low-dimensional Systems & Nanostructures Pub Date : 2024-08-31 DOI:10.1016/j.physe.2024.116096

Han-Lin Liu, J. Wang

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Abstract

The dice lattice bears a similar honeycomb lattice structure to graphene but with a non-dispersive flat band intersecting the Dirac bands at the band center. In this work, we investigate Nernst effect of the dice lattice in a strong magnetic field, focusing on the role of the flat band. By using the Chebyshev polynomial Green’s function method, we show that no Nernst effect ( $S_{x y} = 0$ ) is around the Dirac point in the clean limit contrary to the graphene case because of the existence of a zero Hall conductivity platform. However, an unconventional negative $S_{x y}$ of the double-peak structure emerges instead when the flat band is broadened by disorder and temperature. In addition, when a mass term of Dirac electrons is introduced in the system to open an energy gap, a negative single peak of $S_{x y}$ appears at the Dirac point and this is due to the derivative quantum Hall effect of non-Dirac electrons in the flat band appearing in the energy gap.

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强磁场中骰子晶格的内斯特效应

骰子晶格具有与石墨烯类似的蜂窝晶格结构，但在晶带中心有一个与狄拉克带相交的非色散平带。在这项工作中，我们研究了骰子晶格在强磁场中的能斯特效应，重点是平带的作用。通过使用切比雪夫多项式格林函数方法，我们表明，由于零霍尔电导率平台的存在，与石墨烯的情况相反，在干净的极限中，狄拉克点周围没有纳斯特效应（Sxy=0）。然而，当平坦带因无序和温度而变宽时，双峰结构的非常规负 Sxy 反而会出现。此外，当在系统中引入狄拉克电子的质量项以打开能隙时，在狄拉克点会出现负单峰 Sxy，这是由于平带中的非狄拉克电子的导量子霍尔效应出现在能隙中。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Physica E-low-dimensional Systems & Nanostructures 物理-纳米科技

CiteScore

7.30

自引率

6.10%

发文量

356

审稿时长

65 days

期刊介绍： Physica E: Low-dimensional systems and nanostructures contains papers and invited review articles on the fundamental and applied aspects of physics in low-dimensional electron systems, in semiconductor heterostructures, oxide interfaces, quantum wells and superlattices, quantum wires and dots, novel quantum states of matter such as topological insulators, and Weyl semimetals. Both theoretical and experimental contributions are invited. Topics suitable for publication in this journal include spin related phenomena, optical and transport properties, many-body effects, integer and fractional quantum Hall effects, quantum spin Hall effect, single electron effects and devices, Majorana fermions, and other novel phenomena. Keywords: • topological insulators/superconductors, majorana fermions, Wyel semimetals; • quantum and neuromorphic computing/quantum information physics and devices based on low dimensional systems; • layered superconductivity, low dimensional systems with superconducting proximity effect; • 2D materials such as transition metal dichalcogenides; • oxide heterostructures including ZnO, SrTiO3 etc; • carbon nanostructures (graphene, carbon nanotubes, diamond NV center, etc.) • quantum wells and superlattices; • quantum Hall effect, quantum spin Hall effect, quantum anomalous Hall effect; • optical- and phonons-related phenomena; • magnetic-semiconductor structures; • charge/spin-, magnon-, skyrmion-, Cooper pair- and majorana fermion- transport and tunneling; • ultra-fast nonlinear optical phenomena; • novel devices and applications (such as high performance sensor, solar cell, etc); • novel growth and fabrication techniques for nanostructures