A Weyl Fermion semimetal with surface Fermi arcs in the transition metal monopnictide TaAs class

Shin-Ming Huang; Su-Yang Xu; Ilya Belopolski; Chi-Cheng Lee; Guoqing Chang; BaoKai Wang; Nasser Alidoust; Guang Bian; Madhab Neupane; Chenglong Zhang; Shuang Jia; Arun Bansil; Hsin Lin; M Zahid Hasan

doi:10.1038/ncomms8373

A Weyl Fermion semimetal with surface Fermi arcs in the transition metal monopnictide TaAs class

Nat Commun. 2015 Jun 12:6:7373. doi: 10.1038/ncomms8373.

Authors

Affiliations

¹ 1] Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, 6 Science Drive 2, Singapore 117546, Singapore [2] Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542, Singapore.
² 1] Joseph Henry Laboratory, Department of Physics, Princeton University, Princeton, New Jersey 08544, USA [2] Princeton Center for Complex Materials, Princeton University, Princeton, New Jersey 08544, USA.
³ 1] Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, 6 Science Drive 2, Singapore 117546, Singapore [2] Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542, Singapore [3] Department of Physics, Northeastern University, Boston, Massachusetts 02115, USA.
⁴ Joseph Henry Laboratory, Department of Physics, Princeton University, Princeton, New Jersey 08544, USA.
⁵ 1] Joseph Henry Laboratory, Department of Physics, Princeton University, Princeton, New Jersey 08544, USA [2] Princeton Center for Complex Materials, Princeton University, Princeton, New Jersey 08544, USA [3] Condensed Matter and Magnet Science Group, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
⁶ ICQM, School of Physics, Peking University, Beijing 100871, China.
⁷ 1] ICQM, School of Physics, Peking University, Beijing 100871, China [2] Collaborative Innovation Center of Quantum Matter, Beijing 100871, China.
⁸ Department of Physics, Northeastern University, Boston, Massachusetts 02115, USA.
⁹ 1] Joseph Henry Laboratory, Department of Physics, Princeton University, Princeton, New Jersey 08544, USA [2] Princeton Center for Complex Materials, Princeton University, Princeton, New Jersey 08544, USA [3] Princeton Center for Complex Materials, Princeton University, Princeton, New Jersey 08544, USA.

Abstract

Weyl fermions are massless chiral fermions that play an important role in quantum field theory but have never been observed as fundamental particles. A Weyl semimetal is an unusual crystal that hosts Weyl fermions as quasiparticle excitations and features Fermi arcs on its surface. Such a semimetal not only provides a condensed matter realization of the anomalies in quantum field theories but also demonstrates the topological classification beyond the gapped topological insulators. Here, we identify a topological Weyl semimetal state in the transition metal monopnictide materials class. Our first-principles calculations on TaAs reveal its bulk Weyl fermion cones and surface Fermi arcs. Our results show that in the TaAs-type materials the Weyl semimetal state does not depend on fine-tuning of chemical composition or magnetic order, which opens the door for the experimental realization of Weyl semimetals and Fermi arc surface states in real materials.

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.