Photonic heat transport across a Josephson junction

Abstract

We present a detailed study of photonic heat transport across a Josephson junction coupled to two arbitrary linear circuits having different temperatures. First, we consider the linear approximation, in which a nonlinear Josephson potential is replaced by a quadratic one and the junction acts as an inductor. Afterwards, we discuss the effects of junction anharmonicity. We separately consider the weak-coupling limit, in which the Bloch band structure of the junction energy spectrum plays an important role, and the opposite strong-coupling regime. We apply our general results to two specific models: a Josephson junction coupled to two Ohmic resistors and two resonators. We derive simple analytical approximations for the photonic heat flux in many limiting cases. We demonstrate that electric circuits with embedded Josephson junctions provide a useful platform for quantum thermodynamics experiments. 2 4e 4 E 2 J ω 6 , ω ω J ,

Near-field radiative heat transfer between high-temperature superconductors

“…Closely packed superconducting elements may exhibit changes in their performances due to thermal coupling. The role of heat exchange via conduction in Josephson junctions 1 , 8 , ubiquitous in superconducting technology, has been recently investigated. On the other hand, thermal radiation between contactless superconducting materials may constitute the main heat channel, and thermal management has not been thoroughly investigated.…”

Thermally pumped on-chip maser

“…We derive an explicit expression for the maser power in terms of circuit parameters and show that it can reach up to few femtowatts for typical experimental conditions. This power is several orders of magnitude higher than the lowest power detectable in experiment [23][24][25][26][27][28][29]36,37]. We further show that one can detect the population inversion between the states 0 and 1 without measuring the coherent radiation output of the device.…”

“…The implementation of a heat-driven maser, which allows conversion of heat into coherent radiation, has not yet been discussed in the cQED context. At the same time, significant progress has been recently achieved in integrating the tools of ultrasensitive nanoscale bolometry into cQED devices [23][24][25][26][27][28][29], and a unique platform for studying the heat transport in the quantum limit has been created. Motivated by this progress, here we develop a theory and propose an experimental realization of a thermally driven single-atom maser based on superconducting components.…”

Colloquium: Quantum heat transport in condensed matter systems

“…represents a transmission coefficient. The circuit model for heat transport can be generalized to essentially any linear circuit composed of reactive elements and resistors, as was done by Pascal, Courtois, and Hekking (2011) and Thomas, Pekola, and Golubev (2019).…”