Observation of chiral photocurrent transport in the quantum Hall regime in graphene
arXiv:1903.01487
Abstract
Optical excitation provides a powerful tool to investigate non-equilibrium physics in quantum Hall systems. Moreover, the length scale associated with photo-excited charge carries lies between that of local probes and global transport measurements. Here, we investigate non-equilibrium physics of optically-excited charge carriers in graphene through photocurrent measurements in the integer quantum Hall regime. We observe that the photocurrent oscillates as a function of Fermi level, revealing the Landau-level quantization, and that the photocurrent oscillations are different for Fermi levels near and distant from the Dirac point. Our observation qualitatively agrees with a model that assumes the photocurrent is dominated by chiral edge transport of non-equilibrium carriers. Our experimental results are consistent with electron and hole chiralities being the same when the Fermi level is distant from the Dirac point, and opposite when near the Dirac point.
References in corpus (19)
- Electric Field Effect in Atomically Thin Carbon Films
- Two-Dimensional Gas of Massless Dirac Fermions in Graphene
- Experimental Observation of Quantum Hall Effect and Berry's Phase in Graphene
- Electronic transport in two dimensional graphene
- Thermoelectric and Magnetothermoelectric Transport Measurements of Graphene
- Landau level spectroscopy of ultrathin graphite layers
- Infrared spectroscopy of Landau levels in graphene
- Direct optical detection of Weyl fermion chirality in a topological semimetal
- Scanning tunneling spectroscopy of inhomogeneous electronic structure in monolayer and bilayer graphene on SiC
- Supercurrent in the quantum Hall regime
- Inducing Superconducting Correlation in Quantum Hall Edge States
- The Quantum Hall Transition in Real Space: From Localized to Extended States
- An On/Off Berry Phase Switch in Circular Graphene Resonators
- Large, nonsaturating thermopower in a quantizing magnetic field
- Andreev Reflection in Strong Magnetic Fields
- Charge and Spin Transport at the Quantum Hall Edge of Graphene
- Carrier scattering from dynamical magneto-conductivity in quasi-neutral epitaxial graphene
- Carrier multiplication in graphene under Landau quantization
- Photo-Nernst current in graphene