Engineering a Quantum Thermal Diode with Floquet Driving

Abstract:Controlling heat flow in small quantum systems is a central goal of quantum thermodynamics and nanoscale transport. A key challenge is to achieve strong thermal rectification without suppressing the transmitted heat current, a tradeoff that often arises in static diode configurations. We establish a Floquet-control mechanism in a minimal quantum thermal diode formed by two longitudinally modulated Ising-coupled qubits, each coupled to an independent thermal reservoir. From a microscopic system--bath model, we derive a Floquet--LGKS master equation that resolves the drive-assisted transition channels. The resonant undriven device with left--right symmetric bath couplings serves as the reciprocal benchmark, while static detuning provides a rectifying reference with reduced heat current. Single-side driving breaks this reciprocal structure by creating a Floquet-dressed contact opposite a purely thermal contact. For this configuration, we obtain a compact steady-state current formula and an exact blocking condition for suppressing one bias direction while retaining finite transport in the opposite direction. In the weak sinusoidal-drive regime, rectification begins quadratically in the modulation amplitude. Dual-side driving adds a Floquet pumping contribution to the interaction-mediated current, so complete blocking requires cancellation of both contributions. These results establish contact-selective Floquet dressing as a design principle for controllable heat-flow asymmetry in minimal quantum thermal devices.

3 figures. Comments and suggestions are welcome

arXiv:2607.25678 [quant-ph]

(or arXiv:2607.25678v1 [quant-ph] for this version)

https://doi.org/10.48550/arXiv.2607.25678 Focus to learn more arXiv-issued DOI via DataCite (pending registration)

arXivLabs is a framework that allows collaborators to develop and share new arXiv features directly on our website.

Both individuals and organizations that work with arXivLabs have embraced and accepted our values of openness, community, excellence, and user data privacy. arXiv is committed to these values and only works with partners that adhere to them.

Have an idea for a project that will add value for arXiv's community? Learn more about arXivLabs.