Nonlinear valley thermal physics in two dimensional materials

Abstract

This study delves into the intrinsic nonlinear valley thermal effects, driven by the Quantum Metric of the system. Our findings elucidate that valley indices in the nonlinear effect are distinguishable by the thermoelectric correction to the orbital magnetization, which adopts opposite signs across valleys mirroring the role of orbital angular momentum in the linear valley Hall effect. Through a prototypical two-band model on an anisotropic tilted Dirac semimetal, we investigate how intrinsic material parameters modulate this nonlinear valley thermal response. Extending to realistic PT symmetric anisotropic semiconductors, our findings enrich the understanding of valley-based phenomena, with implications for advanced theoretical and experimental pursuits in valleytronics and valley caloritonics.