An unusual thermoelectric effect has been observed in the semiconductor tellurium by RIKEN physicists for the first time. This demonstration points to the potential of similar materials to be used in applications such as energy harvesting and advanced heat management.

Thermoelectric materials can convert electricity into heat and vice versa. For most of them, doubling the voltage across them will double the heat they produce. But for some special thermoelectric materials, there is a nonlinear relationship between voltage and heat. Such nonlinear thermoelectric materials are useful for applications that require heat to flow in one direction and for generating electricity from thermal fluctuations.

Some theoretical calculations have predicted that even more exotic nonlinear thermoelectric effects will occur in materials where the atoms or molecules have a chiral arrangement. But they hadn’t been observed in the lab—until now.