Conductivity of Dirac fermions with phonon induced topological crossover

Abstract

We study the Hall conductivity in single layer gapped Dirac fermion materials including coupling to a phonon field, which not only modifies the quasi-particle dynamics through the usual self-energy term but also renormalizes directly the gap. Consequently the Berry curvature is modified. As the temperature is increased the sign of the renormalized gap can change and the material can cross over from a band insulator to a topological insulator at higher temperature (T). The effective Chern numbers defined for valley and spin Hall conductivity show a rich phase diagram with increasing temperature. While the spin and valley DC Hall conductivity is no longer quantized at elevated temperature a change in sign with increasing T is a clear indication of a topological crossover. The chirality of the circularly polarized light which is dominantly absorbed by a particular valley can change with temperature as a result of a topological crossover.

6 pages, 5 figures, to appear in Phys. Rev. B

References in corpus (8)

• Electric Field Effect in Atomically Thin Carbon Films
• Two Dimensional Atomic Crystals
• Valley polarization in MoS2 monolayers by optical pumping
• Intrinsic spin Hall effect in monolayers of group-VI dichalcogenides: A first-principles study
• Optical Signatures of the Tunable Band Gap and Valley-Spin Coupling in Silicene
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Cited by in corpus (10)

• Quantized photonic spin Hall effect in graphene
• Phonon-induced topological insulation
• Temperature-induced topological phase transitions: promoted vs. suppressed non-trivial topology
• Optical response of two-dimensional Dirac materials with a flat band
• Curvatronics with bilayer graphene in an effective $4D$ spacetime
• Impact of chemical potential on the reflectance of graphene in the infrared and microwave domains
• Temperature dependence of the topological phase transition of BiTeI from first principles
• Electron-phonon correlations on spin texture of gapped helical Dirac Fermions
• Emergent topological phases and coexistence of gapless and spectral-localized Floquet quantum spin Hall states via electron-phonon interaction
• Topological characterization of magnon-polaron bands and thermal Hall conductivity in a frustrated kagome antiferromagnet