Non-contact imaging detection of thermal Hall effect signature by periodic heating method using lock-in thermography

Abstract

We demonstrate non-contact imaging detection of the thermal Hall effect by means of the lock-in thermography with rotationally asymmetric periodic heating. In the lock-in thermography measurements, we applied periodic laser heating in an elliptical pattern to a sample and measured the temperature modulation oscillating at the same frequency as the heating under a magnetic field. From the magnetic field dependence of the elliptical heating pattern, the temperature modulation due to the thermal Hall effect can be extracted. We confirm the validity of this method by detecting a signature pattern specific to the thermal Hall effect in a Bi slab at room temperature.