Observation of nonlinear thermoelectric effect in MoGe/Y3Fe5O12

• Published in: Nature communications Vol. 15; no. 1; pp. 6912 - 7
• Main Authors: Arisawa, Hiroki, Fujimoto, Yuto, Kikkawa, Takashi, Saitoh, Eiji
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 26.08.2024; Nature Publishing Group; Nature Portfolio
• Subjects: 639/766/119/1003; 639/766/119/997; 639/766/530/2803; 639/766/530/951; Electric potential; Electric power; Fluctuations; Generators; Heat; Heaters; Humanities and Social Sciences; Magnetic fields; Materials research; multidisciplinary; Science; Science (multidisciplinary); Seebeck effect; Temperature distribution; Temperature gradients; Temperature requirements; Thermoelectric power generation; Thermoelectricity; Voltage; Vortices
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-024-50115-4

Thermoelectric effects refer to the voltage generation from temperature gradients in condensed matter. Although various power generators are made from them, all the known effects, such as Seebeck effect, require macroscopic temperature gradients; since the sign of the generated voltage is reversed by reversing the temperature gradient, the net voltage disappears when the temperature distribution fluctuates temporarily or spatially with a macroscopic temperature gradient of zero. It is impossible to utilize such temperature fluctuations in the conventional thermoelectric effects, a situation which limits their application. Here we report the observation of a second-order nonlinear thermoelectric effect; we develop a method to measure nonlinear thermoelectricity and observe that a superconducting MoGe film on Y 3 Fe 5 O 12 generates a voltage proportional to the square of the applied temperature gradient. The nonlinear thermoelectric generation demonstrated here provides a way for making power generators that produce electric power from temperature fluctuations. A second-order nonlinear thermoelectric effect can be used for making power generators using temperature fluctuations. Here, the authors report that a MoGe film on Y 3 Fe 5 O 12 generates a voltage proportional to the square of the temperature gradient.