Thermodynamic and Dynamical Signatures of a Quantum Spin-Hall Insulator to Superconductor Transition

Abstract

Thermodynamic and dynamical properties of a model of Dirac fermions with a deconfined quantum critical point (DQCP) separating an interaction-generated quantum spin-Hall insulator from an s-wave superconductor [Nature Comm.~{\bf 10}, 2658 (2019)] are studied by quantum Monte Carlo simulations. Inside the deconfined quantum critical region bound by the single-particle gap, spinons and spinless charge-2e skyrmions emerge. Since the model conserves total spin and charge, and has a single length scale, these excitations lead to a characteristic linear temperature dependence of the uniform spin and charge susceptibilities. At the DQCP, the order parameter dynamic structure factors show remarkable similarities that support emergent Lorentz symmetry. Above a critical temperature, superconductivity is destroyed by the proliferation of spin-1/2 vortices.

8 pages and 8 figures

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Cited by in corpus (2)

• Critical properties of metallic and deconfined quantum phase transitions in Dirac systems
• Alteration of Topology in Quantum Phase Transitions via Symmetry Enrichment