Cyclotron-resonance-induced photovoltaic effect in high-mobility graphene in the quantum Hall regime

We have investigated the infrared photoinduced voltage $\Delta V$ in high-mobility graphene on hexagonal boron nitride in the quantum Hall regime. We observed $\Delta V$ of up to several $\mu$V at $\nu=\pm 2$ quantum Hall states under the cyclotron resonance conditions. The dependence of $\Delta V$ on the bias current indicates that $\Delta V$ signals derive from the photovoltaic effect rather than the bolometric effect. The dependence of $\Delta V$ on magnetic field direction and measurement geometry suggest the edge channel transport as an origin of photovoltaic effect. $\Delta V$ signals were robust up to $T=180$ K, indicating that $\Delta V$ signals can be used for developing novel terahertz photodetectors operating at high temperatures.