Date and Time: 10-Oct-2022  15:00

Speaker:  Dr.Federico Paolucci, Scientist of Technology, National Institute of Nuclear Physics, Italy

Host: Prof.Ding Zhang ( Tsinghua University ,BAQIS）

Title: Bipolar Thermoelectric Heat Engine

Abstract: 

Thermoelectric effects in metals are typically small due to the nearly perfect particle–hole symmetry around their Fermi surface. Furthermore, thermo-phase effects and linear thermoelectricity in superconducting systems have been identified only when particle–hole symmetry is explicitly broken, since thermoelectric effects were considered impossible in pristine superconductors. In this talk, I will show how superconducting tunnel junctions can develop a very large bipolar thermoelectricity in the presence of a sizable thermal gradient thanks to spontaneous particle–hole symmetry breaking. These junctions show Seebeck coefficients of up to ±300μV/K, which is roughly 105 times larger than the value expected for normal metals at subkelvin temperatures. By integrating the junctions into a Josephson interferometer, it is possible to realize a bipolar phase-tunable heat engine generating electric powers of up to^~140nW/mm² Notably, this device implements also a persistent thermoelectric memory cell, written or erased by current injection.

G. Germanese, F. Paolucci, G. Marchegiani, A. Braggio, and F. Giazotto, Bipolar Thermoelectric Heat Engine, Nature Naotechnology (2022). https://doi.org/10.1038/s41565-022-01208-y

About the Speaker:

Dr. Federico Paolucci did his PhD study in Max Planck Institute for Solid State Research (Stuttgart, Germany) from 2010 to 2015. He then joined the Nanoscience Institute of CNR in (Pisa, Italy) as a post-doc. In 2018, he moved to the National Institute of Nuclear Physics (Pisa, Italy) as a post-doc. In 2020, he moved back to the Nanoscience Institute of CNR in (Pisa, Italy) as Research Staff. Since 2022, he is Scientist of Technology at the National Institute of Nuclear Physics (Pisa, Italy). He is lecturer for of Semiconductor Physics and Quantum Technologies for the Master and PhD program at Scuola Normale Superiore (Pisa, Italy).

Dr. Paolucci is an experimentalist in solid-state matter physics, with the current interest in charge and thermal transport in nanoscale systems at cryogenic temperatures, GHz and THz radiation detectors for astronomy and particle physics, and ultrafast superconducting electronics. He is one of the founders of the CNR spinoff company Digital Superconducting Quantum Machines (DSQM srl) developing filed-effect superconducting electronics.