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Related papers: Discovery of several large families of Topological…

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Topological insulators can be seen as band-insulators with a conducting surface. The surface carriers are Dirac particles with an energy which increases linearly with momentum. This confers extraordinary transport properties characteristic…

Mesoscale and Nanoscale Physics · Physics 2011-12-12 Clément Bouvier , Tristan Meunier , Philippe Ballet , Xavier Baudry , Roman Bernd Günter Kramer , Laurent Lévy

Based on first-principles calculations, we show that stoichiometric TaSe3, synthesized in space group P21/m, belongs to a three-dimensional (3D) strong topological insulator (TI) phase with Z2 invariants (1;100). The calculated surface…

Materials Science · Physics 2018-11-07 Simin Nie , Lingyi Xing , Rongying Jin , Weiwei Xie , Zhijun Wang , Fritz B. Prinz

We study the topological properties of superconductors with paired $j=\frac{3}{2}$ quasiparticles. Higher spin Fermi surfaces can arise, for instance, in strongly spin-orbit coupled band-inverted semimetals. Examples include the Bi-based…

Superconductivity · Physics 2018-03-07 Jörn W. F. Venderbos , Lucile Savary , Jonathan Ruhman , Patrick A. Lee , Liang Fu

Topological crystalline insulators (TCIs) are insulating electronic states with nontrivial topology protected by crystalline symmetries. Recently, theory has proposed new classes of TCIs protected by rotation symmetries \^C$_n$, which have…

Relativistic spin-orbit coupling plays an essential role in the field of topological insulators and quantum spintronics. It gives rise to the topological non-trivial band structure and enables electric manipulation of the spin degree of…

Mesoscale and Nanoscale Physics · Physics 2013-08-07 Haijun Zhang , Chao-Xing Liu , Shou-Cheng Zhang

Relativistic Dirac fermions are ubiquitous in condensed matter physics. Their mass is proportional to the material energy gap and the ability to control and tune the mass has become an essential tool to engineer quantum phenomena that mimic…

Mesoscale and Nanoscale Physics · Physics 2018-08-13 G. Krizman , B. A. Assaf , T. Phuphachong , G. Bauer , G. Springholz , G. Bastard , R. Ferreira , L. A. de Vaulchier , Y. Guldner

A flat band in fermionic system is a dispersionless single-particle state with a diverging effective mass and nearly zero group velocity. These flat bands are expected to support exotic properties in the ground state, which might be…

Topological insulators (TIs) are a new class of quantum materials that exhibit spin momentum locking (SML) of massless Dirac fermions in the surface states. Usually optical methods, such as angle and spin-resolved photoemission…

Mesoscale and Nanoscale Physics · Physics 2016-01-20 André Dankert , Johannes Geurs , M. Venkata Kamalakar , Saroj P. Dash

Semi-metals are characterized by nodal band structures that give rise to exotic electronic properties. The stability of Dirac semi-metals, such as graphene in two spatial dimensions (2D), requires the presence of lattice symmetries, while…

Mesoscale and Nanoscale Physics · Physics 2016-06-15 Robert-Jan Slager , Vladimir Juricic , Ville Lahtinen , Jan Zaanen

The three-dimensional (3D) topological insulator is a novel quantum state of matter where an insulating bulk hosts a linearly-dispersing surface state, which can be viewed as a sea of massless Dirac fermions protected by the time-reversal…

Mesoscale and Nanoscale Physics · Physics 2012-05-17 T. Sato , Kouji Segawa , K. Kosaka , S. Souma , K. Nakayama , K. Eto , T. Minami , Yoichi Ando , T. Takahashi

The interplay between topology and crystalline symmetries in materials can lead to a variety of topological crystalline insulator (TCI) states. Despite significant effort towards their experimental realization, so far only…

Mesoscale and Nanoscale Physics · Physics 2019-11-18 Baokai Wang , Bahadur Singh , Barun Ghosh , Wei-Chi Chiu , M. Mofazzel Hosen , Qitao Zhang , Li Ying , Madhab Neupane , Amit Agarwal , Hsin Lin , Arun Bansil

Topological superconductors are an intriguing and elusive quantum phase, characterized by topologically protected gapless surface/edge states residing in a bulk superconducting gap, which hosts Majorana fermions. Unfortunately, all…

Superconductivity · Physics 2019-05-10 Kyung-Hwan Jin , Huaqing Huang , Jia-Wei Mei , Zheng Liu , Lih-King Lim , Feng Liu

Electrons on the surface of a strong topological insulator, such as Bi2Te3 or Bi1-xSnx, form a topologically protected helical liquid whose excitation spectrum contains an odd number of massless Dirac fermions. A theoretical survey and…

Mesoscale and Nanoscale Physics · Physics 2015-05-14 H. -M. Guo , M. Franz

Topological insulators give rise to exquisite electronic properties due to their spin-momentum locked Dirac-cone-like band structure. Recently, it has been suggested that the required opposite parities between valence and conduction band…

Strongly Correlated Electrons · Physics 2017-01-12 Lin Jiao , Sahana Rößler , D. J. Kim , L. H. Tjeng , Z. Fisk , F. Steglich , S. Wirth

We propose a new type of topological surface modes having cubic dispersion in three-dimensional topological superconductors. Lower order dispersions are prohibited by the threefold rotational symmetry and time-reversal symmetry. Cooper…

Mesoscale and Nanoscale Physics · Physics 2015-04-21 Chen Fang , B. Andrei Bernevig , Matthew J. Gilbert

We construct continuum models of 3D and 4D topological insulators by coupling spin-1/2 fermions to an SU(2) background gauge field, which is equivalent to a spatially dependent spin-orbit coupling. Higher dimensional generalizations of flat…

Strongly Correlated Electrons · Physics 2013-11-01 Yi Li , Shou-Cheng Zhang , Congjun Wu

The Bi$_2$Se$_3$ class of topological insulators has recently been shown to undergo a superconducting transition upon hole or electron doping (Cu$_x$-Bi$_2$Se$_3$ with T$_C$=3.8$^o$K and Pd$_x$-Bi$_2$Te$_3$ with T$_C$=5$^o$K), raising the…

Topological insulators are candidates to open up a novel route in spin based electronics. Different to traditional ferromagnetic materials, where the carrier spin-polarization and magnetization are based on the exchange interaction, the…

In the recently discovered class of materials known as topological insulators, the presence of strong spin-orbit coupling causes certain topological invariants in the bulk to differ from their values in vacuum. The sudden change of…

We investigate states on the surface of strong and weak topological insulators and superconductors that have been gapped by a symmetry breaking term. The surface of a strong 3D topological insulator gapped by a magnetic material is well…

Mesoscale and Nanoscale Physics · Physics 2014-10-07 Ching-Kai Chiu