Thermal transport across a Josephson junction in a dissipative environment

Heat flow in superconducting circuits is emerging as an important theme of research. In this field, the authors make two theoretical advances. First, they demonstrate that heat current across a quantum impurity is expressed compactly in terms of a dynamical susceptibility that fully incorporates many-body physics. Second, they apply their formalism to the Schmid quantum phase transition between superconducting and insulating ground states. They unveil new signatures of that transition in the temperature dependence of thermal conductance, thus motivating further experimental studies.