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Related papers: Topological phase transition induced by band struc…

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We investigate topological band structures of a kagome system coupled to a circularly polarized cavity mode, using a model based on a muffin-tin potential and quantum light-matter interaction. We show that Chern insulating phases emerge in…

Mesoscale and Nanoscale Physics · Physics 2026-04-03 Hikaru Goto , Ryo Okugawa , Takami Tohyama

The high-Chern number phases with a Chern number C>1 have been observed in a recent experiment that performed on the topological insulator (TI) multilayer structures, consisting of the alternating magnetic-doped and undoped TI layers. In…

Mesoscale and Nanoscale Physics · Physics 2021-07-13 Yi-Xiang Wang , Fuxiang Li

A common feature of topological insulators is that they are characterized by topologically invariant quantity such as the Chern number and the $\mathbb{Z}_2$ index. This quantity distinguishes a nontrivial topological system from a trivial…

Strongly Correlated Electrons · Physics 2018-05-24 S. A. Owerre

We study the influence of disorder on the topological transition from a two-dimensional Dirac semi-metal to an insulating state. This transition is described as a continuous merging of two Dirac points leading to a semi-Dirac spectrum at…

Mesoscale and Nanoscale Physics · Physics 2013-07-26 David Carpentier , Andrei A. Fedorenko , Edmond Orignac

Commonly, a two-dimensional topological insulator is characterized by non-zero Chern numbers associated with its band structure. In our work, we present the experimental demonstration of an anomalous topological insulator, for which the…

We demonstrate theoretically that the topology of energy bands and Fermi surface in bilayer graphene undergoes a very sensitive transition when extremely tiny lateral interlayer shift occurs in arbitrary directions. The phenomenon…

Mesoscale and Nanoscale Physics · Physics 2011-10-17 Young-Woo Son , Seon-Myeong Choi , Yoon Pyo Hong , Sungjong Woo , Seung-Hoon Jhi

In this work, we propose a new and simple model that supports Chern semimetals. These new gapless topological phases share several properties with the Chern insulators like a well-defined Chern number associated to each band, topologically…

Mesoscale and Nanoscale Physics · Physics 2015-12-09 Giandomenico Palumbo , Konstantinos Meichanetzidis

We investigate topological characteristics of the photon-dressed band structure of $\alpha$-$\mathcal{T}_3$ lattice on being driven by off-resonant circularly polarized radiation. We obtain exact analytical expressions of the quasienergy…

Mesoscale and Nanoscale Physics · Physics 2019-05-29 Bashab Dey , Tarun Kanti Ghosh

We have performed systematic angle-resolved photoemission spectroscopy of the topological crystalline insulator (TCI) Pb1-xSnxTe to elucidate the evolution of its electronic states across the topological phase transition. As previously…

Mesoscale and Nanoscale Physics · Physics 2013-05-29 Y. Tanaka , T. Sato , K. Nakayama , S. Souma , T. Takahashi , Zhi Ren , M. Novak , Kouji Segawa , Yoichi Ando

Two-dimensional non-interacting fermions without any anti-unitary symmetries generically get Anderson localized in the presence of disorder. In contrast, topological superconductors with their inherent particle-hole symmetry can host a…

Mesoscale and Nanoscale Physics · Physics 2026-01-01 Subrata Pachhal , Naba P. Nayak , Soumya Bera , Adhip Agarwala

Dirac semimetal is a class of semi-metallic phase protected by certain types of crystalline symmetries, and its low-energy effective Hamiltonian is described by Dirac equations in three dimensions (3D). Despite of various theoretical…

Mesoscale and Nanoscale Physics · Physics 2016-05-17 Rui-Xing Zhang , Chao-Xing Liu

The interplay between band topology and magnetism can give rise to exotic states of matter. For example, magnetically doped topological insulators can realize a Chern insulator that exhibits quantized Hall resistance at zero magnetic field.…

We propose a two-dimensional non-Hermitian Chern insulator with inversion symmetry, which is anisotropic and has staggered gain and loss in both x and y directions. In this system, conventional bulk-boundary correspondence holds. The Chern…

Mesoscale and Nanoscale Physics · Physics 2019-10-11 H. C. Wu , L. Jin , Z. Song

Chern insulators are band insulators which exhibit a gap in the bulk and gapless excitations in the edge. Detection of Chern insulators is a serious challenge in cold atoms since the Hall transport measurements are technically unrealistic…

Mesoscale and Nanoscale Physics · Physics 2013-09-30 Xiong-Jun Liu , K. T. Law , T. K. Ng , Patrick A. Lee

The recently discovered topological Dirac semimetal represents a new exotic quantum state of matter. Topological Dirac semimetals can be viewed as three dimensional analogues of graphene, in which the Dirac nodes are protected by…

Mesoscale and Nanoscale Physics · Physics 2017-06-12 Rui Chen , Dong-Hui Xu , Bin Zhou

Manipulating the topological properties of insulators, encoded in invariants such as the Chern number and its generalizations, is now a major issue for realizing novel charge/spin responses in electron systems. We propose that a simple…

Materials Science · Physics 2010-06-30 Jun-ichi Inoue , Akihiro Tanaka

We predict novel topological phases with broken time-reversal symmetry supporting the coexistence of opposite chiral edge states, which are fundamentally different from the photonic spin-Hall, valley-Hall, and higher-order topological…

Mesoscale and Nanoscale Physics · Physics 2024-02-23 H. C. Wu , H. S. Xu , L. C. Xie , L. Jin

A pair of Dirac points (analogous to a vortex-antivortex pair) associated with opposite topological numbers (with $\pm\pi$ Berry phases) can be merged together through parameter tuning and annihilated to gap the Dirac spectrum, offering a…

Mesoscale and Nanoscale Physics · Physics 2019-11-20 Yang Xu , Guodong Jiang , Ireneusz Miotkowski , Rudro R. Biswas , Yong P. Chen

Chern insulator is a building block of many topological quantum matters, ranging from quantum spin Hall insulators to fractional Chern insulators. Here, we discuss a new type of insulator, which consists of two half filled ordinary Chern…

Mesoscale and Nanoscale Physics · Physics 2017-05-24 Li-Jun Lang , Shao-Liang Zhang , Qi Zhou

Topological phase transitions in band models are usually associated to the gap closing between the highest valance band and the lowest conduction band, which can give rise to different types of nodal structures, such as Dirac/Weyl points,…

Mesoscale and Nanoscale Physics · Physics 2024-04-05 Giandomenico Palumbo