Speaker
Description
Accurate modeling of nanoscale transport requires a simultaneous treatment of quantum coherence, interactions, and nonequilibrium environments. While the wide-band limit often enables substantial simplifications, it neglects reservoir spectral structure and can limit the quantitative description of transport and thermodynamic processes. We present a nonequilibrium Green's function framework for open quantum systems beyond the wide-band approximation. Using a finite-bandwidth representation of the reservoirs, the resulting equations of motion retain time-linear scaling while providing direct access to time-dependent charge, energy, and heat currents [1]. The approach enables efficient simulations of interacting quantum junctions coupled to structured environments. Beyond transport calculations, the formalism establishes a connection between nonequilibrium current responses and spectral properties of the central system. In multiterminal geometries, current-voltage characteristics can be used to reconstruct features of the underlying many-body spectrum, providing a transport-based spectroscopic tool [2]. Applications to molecular thermoelectric devices demonstrate how reservoir spectral structure, interactions, and nonequilibrium driving jointly influence energy-conversion efficiency. The framework thus provides a versatile platform for studying and optimizing thermoelectric performance in nanoscale systems operating far from equilibrium [3].
[1] Y. Pavlyukh and R. Tuovinen, Phys. Rev. B 111, L241101 (2025).
[2] Y. Pavlyukh and R. Tuovinen, Eur. Phys. J. Spec. Top. (2025).
[3] R. Tuovinen and Y. Pavlyukh, PRX Energy 4, 043003 (2025).