2021 New Investigator Grant
Linxiao Zhu, Ph.D. John J. and Jean M. Brennan Clean Energy Early Career Assistant Professor of Mechanical Engineering, The Pennsylvania State University
Creating supercurrents in thermal transport
In most transport phenomena, a current is driven by external bias. For example, an electrical or mass current typically occurs when there is a voltage or density gradient, respectively. However, in the phenomenon of supercurrent, a current persists even without any external bias. The discoveries of supercurrents such as in systems exhibiting superconductivity and superfluidity, represent some of the most intriguing effects in modern physics (and have been appropriately responsible for eight Nobel Prizes in physics –1913, 1962, 1972, 1973, 1978, 1987, 1996, and 2003). Heat current is also commonly expected to occur only in the presence of an external bias temperature gradient. Inspired by the fundamental importance of supercurrents in the transport of charge and mass, we propose to experimentally realize supercurrents in thermal transport, i.e., a heat current that persists even in the absence of any temperature gradient. In particular, we will create and probe thermal supercurrent in electromagnetic thermal transport in many-body systems that break the time reversal symmetry, by using semiconductors placed in a magnetic field and magnetic Weyl semimetals. Successful completion of the project will mean the phenomena of supercurrents, which were limited to the transport of charge and mass, will be created in the transport of heat for the first time. We expect this will not only open up exciting opportunities for exploring new physics in the emerging research fields of non-reciprocal and topological thermal transport, but also have important implications for improving renewable energy harvesting such as solar cells and radiative cooling, thermal management and optoelectronics, such as communication.