  Josephson tunnel junctions are proposed as efficient phase-tunable thermal
rectifiers. The latter exploit the strong temperature dependence of the
superconducting density of states and phase-dependence of heat currents flowing
through Josephson junctions to operate. Remarkably, large heat rectification
coefficients up to 800% can potentially be achieved using conventional
materials and standard fabrication methods. In addition, these devices allow
for the in-situ fine tuning of the thermal rectification magnitude and
direction.
