title: Observation of a three-dimensional topological Dirac semimetal phase in high-mobility Cd3As2.
abstract: Symmetry-broken three-dimensional (3D) topological Dirac semimetal systems with strong spin-orbit coupling can host many exotic Hall-like phenomena and Weyl fermion quantum transport. Here, using high-resolution angle-resolved photoemission spectroscopy, we performed systematic electronic structure studies on Cd3As2, which has been predicted to be the parent material, from which many unusual topological phases can be derived. We observe a highly linear bulk band crossing to form a 3D dispersive Dirac cone projected at the Brillouin zone centre by studying the (001)-cleaved surface. Remarkably, an unusually high in-plane Fermi velocity up to 1.5×10(6) ms(-1) is observed in our samples, where the mobility is known up to 40,000 cm2 V(-1) s(-1), suggesting that Cd3As2 can be a promising candidate as an anisotropic-hypercone (three-dimensional) high spin-orbit analogue of 3D graphene. Our discovery of the Dirac-like bulk topological semimetal phase in Cd3As2 opens the door for exploring higher dimensional spin-orbit Dirac physics in a real material.
authors.affiliation: 1] Joseph Henry Laboratory, Department of Physics, Princeton University, Princeton, New Jersey 08544, USA [2].
authors.forename: Madhab
authors.initials: M
authors.lastname: Neupane
authors.affiliation: 1] Joseph Henry Laboratory, Department of Physics, Princeton University, Princeton, New Jersey 08544, USA [2].
authors.forename: Su-Yang
authors.initials: SY
authors.lastname: Xu
authors.affiliation: 1] Center for Condensed Matter Sciences, National Taiwan University, Taipei 10617, Taiwan [2].
authors.forename: Raman
authors.initials: R
authors.lastname: Sankar
authors.affiliation: Joseph Henry Laboratory, Department of Physics, Princeton University, Princeton, New Jersey 08544, USA.
authors.forename: Nasser
authors.initials: N
authors.lastname: Alidoust
authors.affiliation: Joseph Henry Laboratory, Department of Physics, Princeton University, Princeton, New Jersey 08544, USA.
authors.forename: Guang
authors.initials: G
authors.lastname: Bian
authors.affiliation: Joseph Henry Laboratory, Department of Physics, Princeton University, Princeton, New Jersey 08544, USA.
authors.forename: Chang
authors.initials: C
authors.lastname: Liu
authors.affiliation: Joseph Henry Laboratory, Department of Physics, Princeton University, Princeton, New Jersey 08544, USA.
authors.forename: Ilya
authors.initials: I
authors.lastname: Belopolski
authors.affiliation: Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan.
authors.forename: Tay-Rong
authors.initials: TR
authors.lastname: Chang
authors.affiliation: 1] Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan [2] Institute of Physics, Academia Sinica, Taipei 11529, Taiwan.
authors.forename: Horng-Tay
authors.initials: HT
authors.lastname: Jeng
authors.affiliation: Graphene Research Centre, Department of Physics, National University of Singapore, Singapore 117542, Singapore.
authors.forename: Hsin
authors.initials: H
authors.lastname: Lin
authors.affiliation: Department of Physics, Northeastern University, Boston, Massachusetts 02115, USA.
authors.forename: Arun
authors.initials: A
authors.lastname: Bansil
authors.affiliation: Center for Condensed Matter Sciences, National Taiwan University, Taipei 10617, Taiwan.
authors.forename: Fangcheng
authors.initials: F
authors.lastname: Chou
authors.affiliation: 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.
authors.forename: M Zahid
authors.initials: MZ
authors.lastname: Hasan