Topological phase transition under pressure in the topological nodal-line superconductor PbTaSe2
Journal
Physical Review B
Journal Volume
96
Journal Issue
6
Pages
064528-1 - 064528-7
Date Issued
2017
Author(s)
Xu, C. Q.
Sankar, R.
Zhou, W.
Li, B.
Han, Z. D.
Qian, B.
Dai, J. H.
Cui, H.
Bangura, A. F.
Xu, X.
Abstract
A first-order-like resistivity hysteresis is induced by a subtle structural transition under hydrostatic pressure in the topological nodal-line superconductor PbTaSe2. This structure transition is quickly suppressed to zero at pressure ∼0.25 GPa. As a result, superconductivity shows a marked suppression, accompanied with pronounced changes in the magnetoresistance and Hall resistivity. The first-principles calculations show that the spin-orbit interactions partially gap out the Dirac nodal line around K point in the bulk Brillouin zone upon applying a small pressure, whereas the Dirac states around H point are completely destroyed. The calculations further reveal a second structural phase transition under a pressure as high as ∼30 GPa, through which a transition from a topologically nontrivial bulk phase to a trivial phase is uncovered, with a superconducting dome emerging under this high-pressure phase. Our calculations also reveal how the bulk Fermi surfaces and the surface bands evolve with pressure. This theoretical study shall inspire in-depth experimental investigations on the electronic structure of this novel topological superconductor under higher pressures.
Publisher
American Physical Society
Type
journal article