We propose theoretically a thermal switch operating by the magnetic-flux controlled diffraction of phase-coherent heat currents in a thermally biased Josephson junction based on a two-dimensional topological insulator. For short junctions, the system shows a sharp switching behavior while for long junctions the switching is smooth. Physically, the switching arises from the Doppler shift of the superconducting condensate due to screening currents induced by a magnetic flux. We suggest a possible experimental realization that exhibits a relative temperature change of 40\% between the on and off state for realistic parameters. This is a factor of two larger than in recently realized thermal modulators based on conventional superconducting tunnel junctions.
@article{arxiv.1610.06099,
title = {High efficiency thermal switch based on topological Josephson junctions},
author = {Björn Sothmann and Francesco Giazotto and Ewelina M. Hankiewicz},
journal= {arXiv preprint arXiv:1610.06099},
year = {2017}
}