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 (19)

• Atomically thin MoS2: A new direct-gap semiconductor
• Berry Phase Effects on Electronic Properties
• Coupled spin and valley physics in monolayers of MoS2 and other group-VI dichalcogenides
• Anomalous Hall effect
• Topological Field Theory of Time-Reversal Invariant Insulators
• Valley contrasting physics in graphene: magnetic moment and topological transport
• The Valley Hall Effect in MoS2 Transistors
• Massive Dirac fermions and Hofstadter butterfly in a van der Waals heterostructure
• Valley Dependent Optoelectronics from Inversion Symmetry Breaking
• Magnetoelectric polarizability and axion electrodynamics in crystalline insulators
• Commensurate-incommensurate transition for graphene on hexagonal boron nitride
• Detecting Topological Currents in Graphene Superlattices
• Snapshots of non-equilibrium Dirac carrier distributions in graphene
• Generation and detection of pure valley current by electrically induced Berry curvature in bilayer graphene
• Direct view on the ultrafast carrier dynamics in graphene
• Gate-tunable Topological Valley Transport in Bilayer Graphene
• Observation of an intrinsic bandgap and Landau level renormalization in graphene/boron-nitride heterostructures
• Topological Valley Currents in Gapped Dirac Materials
• Conformal Invariance and Shape-Dependent Conductance of Graphene Samples

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• Photocurrent as a multi-physics diagnostic of quantum materials
• Probing topology by "heating": Quantized circular dichroism in ultracold atoms
• Tunable and giant valley-selective Hall effect in gapped bilayer graphene
• Magnetoresistance of a three-dimensional Dirac gas
• Theory of plasmonic edge states in chiral bilayer systems
• Unidirectional plasmonic edge modes on general two-dimensional materials
• Layer photovoltaic effect in van der Waals heterostructures
• Controlling the orbital Hall effect in gapped bilayer graphene in the terahertz regime
• Electro-Optics of Current-carrying Graphene
• Optical absorption in interacting and nonlinear Weyl semimetals