skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Electronic band tuning under pressure in MoTe2 topological semimetal

Journal Article · · npj Quantum Materials

Abstract Topological superconductors (TSC) can host exotic quasiparticles such as Majorana fermions, poised as the fundamental qubits for quantum computers. TSC’s are predicted to form a superconducting gap in the bulk, and gapless surface/edges states which can lead to the emergence of Majorana zero energy modes. A candidate TSC is the layered dichalcogenide MoTe 2 , a type-II Weyl (semi)metal in the non-centrosymmetric orthorhombic (T d ) phase. It becomes superconducting upon cooling below 0.25 K, while under pressure, superconductivity extends well beyond the structural boundary between the orthorhombic and monoclinic (1T′) phases. Here, we show that under pressure, coupled with the electronic band transition across the T d to 1T′ phase boundary, evidence for a new phase, we call T d * is observed and appears as the volume fraction of the T d phase decreases in the coexistence region. T d * is most likely centrosymmetric. In the region of space where T d * appears, Weyl nodes are destroyed. T d * disappears upon entering the monoclinic phase as a function of temperature or on approaching the suppression of the orthorhombic phase under pressure above 1 GPa. Our calculations in the orthorhombic phase under pressure show significant band tilting around the Weyl nodes that most likely changes the spin-orbital texture of the electron and hole pockets near the Fermi surface under pressure that may be linked to the observed suppression of magnetoresistance with pressure.

Research Organization:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Basic Energy Sciences (BES)
Grant/Contract Number:
AC05-00OR22725; FG02-01ER45927
OSTI ID:
1619754
Alternate ID(s):
OSTI ID: 1561665
Journal Information:
npj Quantum Materials, Journal Name: npj Quantum Materials Vol. 4 Journal Issue: 1; ISSN 2397-4648
Publisher:
Nature Publishing GroupCopyright Statement
Country of Publication:
United Kingdom
Language:
English
Citation Metrics:
Cited by: 15 works
Citation information provided by
Web of Science

References (20)

Elastic and electronic tuning of magnetoresistance in MoTe 2 journal December 2017
The crystal structures of WTe 2 and high-temperature MoTe 2 journal February 1966
Origin of extremely large magnetoresistance in the candidate type-II Weyl semimetal MoTe2−x journal September 2018
Spectroscopic evidence for a type II Weyl semimetallic state in MoTe2 journal July 2016
Type-II Weyl semimetals journal November 2015
Band structure and optical response of 2 H Mo X 2 compounds ( X = S , Se, and Te) journal April 2005
A low-temperature structural phase transition in β-MoTe 2 journal August 1978
Emergence of topologically protected states in the MoTe 2 Weyl semimetal with layer-stacking order journal April 2019
Time-Reversal-Invariant Topological Superconductors and Superfluids in Two and Three Dimensions journal May 2009
Topological Materials: Weyl Semimetals journal March 2017
Mechanical control of crystal symmetry and superconductivity in Weyl semimetal MoTe 2 journal July 2018
The crystal structure of MoTe 2 journal June 1961
Superconductivity in type-II Weyl semimetals journal April 2017
Quantum anomalies in superconducting Weyl metals journal May 2016
Superconductivity in Weyl semimetal candidate MoTe2 journal March 2016
Electrical resistivity anomaly in β-MoTe 2 (metallic behaviour) journal February 1978
Bandgap opening in few-layered monoclinic MoTe2 journal May 2015
Experimental observation of topological Fermi arcs in type-II Weyl semimetal MoTe2 journal September 2016
Signatures of the topological s +− superconducting order parameter in the type-II Weyl semimetal T d-MoTe2 journal October 2017
Discovery of a Weyl fermion semimetal and topological Fermi arcs journal July 2015

Figures / Tables (5)


Similar Records

Elastic and electronic tuning of magnetoresistance in MoTe2
Journal Article · Fri Dec 15 00:00:00 EST 2017 · Science Advances · OSTI ID:1619754

Emergence of topologically protected states in the MoTe2 Weyl semimetal with layer-stacking order
Journal Article · Mon Apr 08 00:00:00 EDT 2019 · Physical Review B · OSTI ID:1619754

Quantum oscillations from networked topological interfaces in a Weyl semimetal
Journal Article · Mon Sep 07 00:00:00 EDT 2020 · npj Quantum Materials · OSTI ID:1619754