- Open Access
Thermoelectric Energy Conversion in Molecular Junctions Out of Equilibrium
PRX Energy 4, 043003 – Published 15 October, 2025
DOI: https://doi.org/10.1103/rj3h-8z3g
Abstract
Understanding time-resolved quantum transport is crucial for developing next-generation quantum technologies, particularly in nano- and molecular junctions subjected to time-dependent perturbations. Traditional steady-state approaches to quantum transport are not designed to capture the transient dynamics necessary for controlling electronic behavior at ultrafast timescales. In this work, we present a nonequilibrium Green’s function formalism, within the recently developed iterated generalized Kadanoff-Baym ansatz (), to study thermoelectric quantum transport beyond the wide-band limit approximation (WBLA). We employ the Meir-Wingreen formula for both charge and energy currents and analyze the transition from Lorentzian line-width functions to the WBLA, identifying unphysical divergences in the latter. Our results highlight the importance of finite-bandwidth effects and demonstrate the efficiency of the approach in modeling time-resolved thermoelectric transport, also providing benchmark comparisons against the full Kadanoff-Baym theory. We exemplify the developed theory in the calculation of time-resolved thermopower and thermoelectric energy conversion efficiency in a cyclobutadiene molecular junction.
Physics Subject Headings (PhySH)
Popular Summary
Thermoelectric effects, long used in space applications and scientific instrumentation, are now being explored at nanometer scales and femtosecond timescales. We introduce a computational framework based on non-equilibrium Green's functions to describe time-resolved charge and heat transport in molecular junctions under out-of-equilibrium conditions. The method captures memory effects and allows accurate calculation of energy currents without relying on the wide-band limit approximation for leads.
Benchmarking against Kadanoff-Baym equations shows excellent agreement with significantly reduced computational cost. The formalism yields time-dependent transport coefficients and a transient figure of merit, offering insights relevant for nanoscale thermoelectric optimization. Potential applications include heat management in photodetectors and ultrafast thermoelectric bolometers for qubit readout in quantum computing.
Article Text
Supplemental Material
References (113)
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