{"title":"Nernst effect of the dice lattice in a strong magnetic field","authors":"","doi":"10.1016/j.physe.2024.116096","DOIUrl":null,"url":null,"abstract":"<div><p>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 (<span><math><mrow><msub><mrow><mi>S</mi></mrow><mrow><mi>x</mi><mi>y</mi></mrow></msub><mo>=</mo><mn>0</mn></mrow></math></span>) 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 <span><math><msub><mrow><mi>S</mi></mrow><mrow><mi>x</mi><mi>y</mi></mrow></msub></math></span> 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 <span><math><msub><mrow><mi>S</mi></mrow><mrow><mi>x</mi><mi>y</mi></mrow></msub></math></span> 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.</p></div>","PeriodicalId":20181,"journal":{"name":"Physica E-low-dimensional Systems & Nanostructures","volume":null,"pages":null},"PeriodicalIF":2.9000,"publicationDate":"2024-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Physica E-low-dimensional Systems & Nanostructures","FirstCategoryId":"101","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1386947724002005","RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"NANOSCIENCE & NANOTECHNOLOGY","Score":null,"Total":0}
引用次数: 0
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 () 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 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 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.
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