Giant Hall photoconductivity in narrow-gapped Dirac materials

Abstract

Carrier dynamics acquire a new character in the presence of Bloch-band Berry curvature, which naturally arises in gapped Dirac materials (GDMs). Here we argue that photoresponse in GDMs with small band gaps is dramatically enhanced by Berry curvature. This manifests in a giant and saturable Hall photoconductivity when illuminated by circularly polarized light. Unlike Hall motion arising from a Lorentz force in a magnetic field, which impedes longitudinal carrier motion, Hall photoconductivity arising from Berry curvature can boost longitudinal carrier transport. In GDMs, this results in a helicity-dependent photoresponse in the Hall regime, where photoconductivity is dominated by its Hall component. We find that the induced Hall conductivity per incident irradiance is enhanced by up to six orders of magnitude when moving from the visible regime (with corresponding band gaps) to the far infrared. These results suggest that narrow-gap GDMs are an ideal test-bed for the unique physics that arise in the presence of Berry curvature, and open a new avenue for infrared and terahertz optoelectronics.

References in corpus (6)

• Topological Field Theory of Time-Reversal Invariant Insulators
• The Valley Hall Effect in MoS2 Transistors
• Valley Dependent Optoelectronics from Inversion Symmetry Breaking
• Detecting Topological Currents in Graphene Superlattices
• Observation of an intrinsic bandgap and Landau level renormalization in graphene/boron-nitride heterostructures
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Cited by in corpus (6)

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• Tunable and giant valley-selective Hall effect in gapped bilayer graphene
• Theory of plasmonic edge states in chiral bilayer systems
• Unidirectional plasmonic edge modes on general two-dimensional materials
• Controlling the orbital Hall effect in gapped bilayer graphene in the terahertz regime
• Layer photovoltaic effect in van der Waals heterostructures