Quantum Bipolar Thermoelectricity

TL;DR

This paper uncovers a purely quantum mechanism for bipolar thermoelectricity in superconducting tunnel junctions, enabling environmentally sensitive spectroscopic sensing and low-temperature thermoelectric device design.

Contribution

It reveals a novel quantum thermoelectric effect arising from dynamical Coulomb blockade and electromagnetic bath interactions in superconducting junctions.

Findings

Seebeck coefficients up to 100 μV/K demonstrated.

The thermoelectric response reflects environmental spectral properties.

Potential applications in environmental sensing and low-temperature thermoelectric devices.

Abstract

Thermoelectricity is generally understood as a classical effect emerging from energy-dependent transport asymmetries. Here we uncover a purely quantum mechanism, where a superconducting S-I-S' tunnel junction in thermal equilibrium develops a nonlinear bipolar thermoelectric response owing to the dynamical Coulomb blockade and the emission-absorption imbalance of a cold electromagnetic bath. Two representative environments are analysed, revealing Seebeck coefficients up to 100 $\mu$V/K for realistic junction parameters. Because the response directly reflects the spectral properties of the surrounding environment, our results suggest that bipolar quantum thermoelectricity could provide a new route for spectroscopic sensing of electromagnetic modes and for designing low-temperature thermoelectric devices with environmentally engineered performance.