Fully balanced heat interferometer

A tunable and balanced heat interferometer is proposed and analyzed. The device consists of two superconductors linked together to form a double-loop interrupted by three parallel-coupled Josephson junctions. Both superconductors are held at different temperatures, allowing the heat currents flowing through the structure to interfere. We demonstrate that thermal transport is coherently modulated through the application of a magnetic flux. Furthermore, such modulation can be tailored at will or even suppressed through the application of an extra control flux. Such a device allows for a versatile operation appearing as an attractive key to the onset of low-temperature coherent caloritronic circuits. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4794412]