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Related papers: Crystalline finite-size topology

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We theoretically predict two new classes of three-dimensional topological crystalline insulators (TCIs), which have an odd number of unpinned surface Dirac cones protected by crystal symmetries. The first class is protected by a single…

Mesoscale and Nanoscale Physics · Physics 2015-04-16 Chen Fang , Liang Fu

Protection of topological surface states by reflection symmetry breaks down when the boundary of the sample is misaligned with one of the high symmetry planes of the crystal. We demonstrate that this limitation is removed in amorphous…

Mesoscale and Nanoscale Physics · Physics 2021-08-10 Helene Spring , Anton R. Akhmerov , Daniel Varjas

With the rapid development of topological states in crystals, the study of topological states has been extended to quasicrystals in recent years. In this review, we summarize the recent progress of topological states in quasicrystals,…

Materials Science · Physics 2021-08-04 Jiahao Fan , Huaqing Huang

Topological crystalline insulators define a new class of topological insulator phases with gapless surface states protected by crystalline symmetries. In this work, we present a general theory to classify topological crystalline insulator…

Mesoscale and Nanoscale Physics · Physics 2016-01-29 Xiao-Yu Dong , Chao-Xing Liu

Symmetry and topology are two fundamental aspects of many quantum states of matter. Recently, new topological materials, higher-order topological insulators, were discovered, featuring, e.g., bulk-edge-corner correspondence that goes beyond…

We explore the 32 crystallographic point groups and identify topological phases of matter with robust surface modes. For n =3,4 and 6 of the C_{nv} groups, we find the first-known 3D topological insulators without spin-orbit coupling, and…

Strongly Correlated Electrons · Physics 2014-09-17 A. Alexandradinata , Chen Fang , Matthew J. Gilbert , B. Andrei Bernevig

Time Reversal Symmetry (TRS) broken topological phases provide gapless surface states protected by topology, regardless of additional internal symmetries, spin or valley degrees of freedom. Despite the numerous demonstrations of 2D…

Recent theoretical advances have proposed a new class of topological crystalline insulator (TCI) phases protected by rotational symmetries. Distinct from topological insulators (TIs), rotational symmetry-protected TCIs are expected to show…

We show that topological characterization and classification in $D$-dimensional systems, which are thermodynamically large in only $D-\delta$ dimensions and finite in size in $\delta$ dimensions, is fundamentally different from that of…

Mesoscale and Nanoscale Physics · Physics 2023-08-01 Ashley M. Cook , Anne E. B. Nielsen

In recent years, higher-order topological phases have attracted great interest in various fields of physics. These phases have protected boundary states at lower-dimensional boundaries than the conventional first-order topological phases…

Mesoscale and Nanoscale Physics · Physics 2024-04-19 Yan-Bin Yang , Jiong-Hao Wang , Kai Li , Yong Xu

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

In this work we consider whether nonsymmorphic symmetries such as a glide plane can protect the existence of topological crystalline insulators and superconductors in three dimensions. In analogy to time-reversal symmetric insulators, we…

Strongly Correlated Electrons · Physics 2015-11-11 Daniel Varjas , Fernando de Juan , Yuan-Ming Lu

We complete a classification of topological phases and their topological defects in crystalline insulators and superconductors. We consider topological phases and defects described by non-interacting Bloch and Bogoliubov de Gennes…

Mesoscale and Nanoscale Physics · Physics 2014-10-15 Ken Shiozaki , Masatoshi Sato

While the experimental progress on three dimensional topological insulators is rapid, the development of their two dimensional counterparts has been comparatively slow, despite their technological promise. The main reason is materials…

Mesoscale and Nanoscale Physics · Physics 2015-06-10 M. Kindermann

A 3D fermionic topological insulator has a gapless Dirac surface state protected by time-reversal symmetry and charge conservation symmetry. The surface state can be gapped by introducing ferromagnetism to break time-reversal symmetry,…

Strongly Correlated Electrons · Physics 2013-09-24 Parsa Bonderson , Chetan Nayak , Xiao-Liang Qi

Topological phases, especially topological crystalline insulators (TCIs), have been intensively explored observed experimentally in three-dimensional (3D) materials. However, the two-dimensional (2D) films are explored much less than 3D…

Materials Science · Physics 2017-11-22 Yi-zhen Jia , Wei-xiao Ji , Chang-wen Zhang , Ping Li , Shu-feng Zhang , Pei-ji Wang , Sheng-shi Li , Shi-shen Yan

Topological crystalline insulators (TCIs) are classified by topological invariants defined with respect to the crystalline symmetries of their gapped bulk. The bulk-boundary correspondence then links the topological properties of the bulk…

Mesoscale and Nanoscale Physics · Physics 2024-12-24 Gengming Liu , Violet Workman , Jiho Noh , Yuhao Ma , Taylor L. Hughes , Wladimir A. Benalcazar , Gaurav Bahl

We study second-order topological insulators and semimetals characterized by chiral symmetry. We investigate topological phase transitions of a model for construction of the two-dimensional second-order topological insulators protected only…

Mesoscale and Nanoscale Physics · Physics 2019-12-06 Ryo Okugawa , Shin Hayashi , Takeshi Nakanishi

We demonstrate that rotation symmetry is not a necessary requirement for the existence of fractional corner charges in Cn-symmetric higher-order topological crystalline insulators. Instead, it is sufficient to have a latent rotation…

Mesoscale and Nanoscale Physics · Physics 2025-02-26 L. Eek , M. Röntgen , A. Moustaj , C. Morais Smith

In an ordinary three-dimensional metal the Fermi surface forms a two-dimensional closed sheet separating the filled from the empty states. Topological semimetals, on the other hand, can exhibit protected one-dimensional Fermi lines or…

Mesoscale and Nanoscale Physics · Physics 2016-05-24 Y. -H. Chan , Ching-Kai Chiu , M. Y. Chou , Andreas P. Schnyder