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Related papers: Weyl points of mechanical diamond

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Topological mechanical structures exhibit robust properties protected by topological invariants. In this letter, we study a family of deformed square lattices that display topologically protected zero-energy bulk modes analogous to the…

Mesoscale and Nanoscale Physics · Physics 2016-04-06 D. Zeb Rocklin , Bryan Gin-ge Chen , Martin Falk , Vincenzo Vitelli , T. C. Lubensky

Nonsymmoprhic symmetries, such as screw rotations or glide reflections, can enforce band crossings within high-symmetry lines or planes of the Brillouin zone. When these band degeneracies are close to the Fermi energy, they can give rise to…

We introduce a general mechanism for obtaining Weyl points in a stack of 2D quasicrystals, which can be extended to any stack of aperiodic layers. We do so by driving a topological phase transition with the vertical crystal-momentum as the…

Mesoscale and Nanoscale Physics · Physics 2023-09-21 André Grossi e Fonseca , Thomas Christensen , John D. Joannopoulos , Marin Soljačić

Constrained by the Nielsen-Ninomiya no-go theorem, in all so-far experimentally determined Weyl semimetals (WSMs) the Weyl points (WPs) always appear in pairs in the momentum space with no exception. As a consequence, Fermi arcs occur on…

We propose to realize Weyl semimetals in a cubic optical lattice. We find that there exist three distinct Weyl semimetal phases in the cubic optical lattice for different parameter ranges. One of them has two pairs of Weyl points and the…

Strongly Correlated Electrons · Physics 2017-07-18 Jing-Min Hou , Wei Chen

In 1929, Hermann Weyl derived the massless solutions from the Dirac equation - the relativistic wave equation for electrons. Neutrinos were thought, for decades, to be Weyl fermions until the discovery of the neutrino mass. Moreover, it has…

Materials Science · Physics 2016-10-31 Ling Lu , Zhiyu Wang , Dexin Ye , Lixin Ran , Liang Fu , John D. Joannopoulos , Marin Soljačić

Weyl metal is the first example of a conducting material with a nontrivial electronic structure topology, making it distinct from an ordinary metal. Unlike in insulators, the nontrivial topology is not related to invariants, associated with…

Mesoscale and Nanoscale Physics · Physics 2018-05-23 A. A. Burkov

A family of topological semimetallic phases where twofold degenerate gapless points form linked rings is introduced. We refer to this phase as Weyl-link semimetals. A concrete two-band model with two linked nodal lines is constructed. We…

Mesoscale and Nanoscale Physics · Physics 2017-08-30 Po-Yao Chang , Chuck-Hou Yee

Controllability of ultracold atomic gases has reached an unprecedented level, allowing for experimental realization of the long-sought-after Thouless pump, which can be interpreted as a dynamical quantum Hall effect. On the other hand, Weyl…

Quantum Gases · Physics 2018-11-14 Yan-Bin Yang , L. -M. Duan , Yong Xu

Weyl fermions can arise from time-reversal symmetry-breaking magnetism, but their impact on magnetic order is a source of ongoing research. Using high-precision neutron diffraction and spectroscopy, we present a comprehensive exploration of…

We consider three-dimensional fermionic band theories that exhibit Weyl nodal surfaces defined as two-band degeneracies that form closed surfaces in the Brillouin zone. We demonstrate that topology ensures robustness of these objects under…

Mesoscale and Nanoscale Physics · Physics 2018-03-01 Oğuz Türker , Sergej Moroz

Materials adopting the diamond structure possess useful properties in atomic and colloidal systems, and are a popular target for synthesis in colloids where a photonic band gap is possible. The desirable photonic properties of the diamond…

When a Dirac semimetal is subject to a circularly polarized laser, it is predicted that the Dirac cone splits into two Weyl nodes and a nonequilibrium transient state called the Floquet Weyl semimetal is realized. We focus on the previously…

Mesoscale and Nanoscale Physics · Physics 2017-08-02 Leda Bucciantini , Sthitadhi Roy , Sota Kitamura , Takashi Oka

As they do not rely on the presence of any crystal symmetry, Weyl nodes are robust topological features of an electronic structure that can occur at any momentum and energy. Acting as sinks and sources of Berry curvature, Weyl nodes have…

Based on first principle calculations, we show that a family of nonmagnetic materials including TaAs, TaP, NbAs and NbP are Weyl semimetal (WSM) without inversion center. We find twelve pairs of Weyl points in the whole Brillouin zone (BZ)…

Materials Science · Physics 2015-03-19 Hongming Weng , Chen Fang , Zhong Fang , Andrei Bernevig , Xi Dai

We match analytic results to numerical calculations to provide a detailed picture of the metal-insulator and topological transitions found in density functional plus cluster dynamical mean-field calculations of pyrochlore iridates. We…

Strongly Correlated Electrons · Physics 2017-11-30 Runzhi Wang , Ara Go , Andrew Millis

Weyl points in three-dimensional photonic crystals behave as monopoles of Berry flux in momentum space. Here, based on general symmetry analysis, we show that a minimal number of four symmetry-related (consequently equifrequency) Weyl…

Mesoscale and Nanoscale Physics · Physics 2016-07-06 Luyang Wang , Shao-Kai Jian , Hong Yao

We generalize the concept of Berry connection of the single-electron band structure to the two-particle Cooper pair states between two Fermi surfaces with opposite Chern numbers. Because of underlying Fermi surface topology, the pairing…

Strongly Correlated Electrons · Physics 2018-02-14 Yi Li , F. D. M. Haldane

By a uniform and simple Weyl invariant coupling of scale and matter fields, we construct theories that unify massless, massive, and partially massless excitations. Masses are related to tractor Weyl weights, and Breitenlohner-Freedman…

High Energy Physics - Theory · Physics 2014-11-18 A. R. Gover , A. Shaukat , A. Waldron

Unconventional superconducting states of matter are realized in the presence of strong spin orbit coupling. In particular, non degenerate bands can support odd parity superconductivity with rich topological content. Here we study whether…

Superconductivity · Physics 2015-06-16 Huazhou Wei , Sung-Po Chao , Vivek Aji