Professor Eiji Saito and his research group have succeeded in demonstrating a ‘nonlinear’ thermoelectric effect, which makes use of the existence of temperature fluctuations, which are spatial and temporal temperature fluctuations on a microscopic scale, even in materials with seemingly no temperature gradient. In order to utilize the temperature fluctuations, they developed a measurement method to selectively detect the ‘nonlinear’ thermoelectric effect, in which an electric field proportional to the square of the temperature gradient is generated, and found that the thermoelectric voltage in a superconductor MoGe thin film fabricated on the magnetic material Y2Fe5O12 shows a second-order nonlinearity with respect to the input temperature gradient. This achievement creates the possibility of an operating principle for sensors that detect non-equilibrium temperature fluctuations and a completely new environmental power generation device that can generate electricity from non-equilibrium temperature fluctuations under conditions where there is no macroscopic temperature gradient. The resulting paper was published in the British scientific journal Nature Communications on 26 August.
[Link]