Anticorrelation between polar lattice instability and superconductivity in the Weyl semimetal candidate MoTe2

Abstract

The relation between the polar structural instability and superconductivity in a Weyl semimetal candidate MoTe2 has been clarified by finely controlled physical and chemical pressure. The physical pressure as well as the chemical pressure, i.e., the Se substitution for Te, enhances the superconducting transition temperature Tc at around the critical pressure where the polar structure transition disappears. From the heat capacity and thermopower measurements, we ascribe the significant enhancement of Tc at the critical pressure to a subtle modification of the phonon dispersion or the semimetallic band structure upon the polar-to-nonpolar transition. On the other hand, the physical pressure, which strongly reduces the interlayer distance, is more effective on the suppression of the polar structural transition and the enhancement of Tc as compared with the chemical pressure, which emphasizes the importance of the interlayer coupling on the structural and superconducting instability in MoTe2.

5 pages, 4 figures

References in corpus (5)

• Titanic Magnetoresistance in WTe2
• Topological spin-current in non-centrosymmetric superconductors
• Superconductivity of doped Weyl semimetals: finite-momentum pairing and electronic analogues of the 3He-A phase
• Activation of new Raman modes by inversion symmetry breaking in type II Weyl semimetal candidate T'-MoTe2
• Critical enhancement of thermopower in a chemically tuned polar semimetal MoTe${}_2$

Cited by in corpus (5)

• Ab initio approach to the elastic, electronic, and optical properties of MoTe2: A topological Weyl semimetal
• Topological phase transition between distinctWeyl semimetal states in MoTe2
• Angular dependence of the upper critical field in the high-pressure $1T^{\prime }$ phase of MoTe${}_2$
• Giant enhancement of cryogenic thermopower by polar structural instability in the pressurized semimetal MoTe2
• Negative thermal expansion near two structural quantum phase transitions