Refrigerator based on the Coulomb barrier for single-electron tunneling

We propose a remarkably simple electronic refrigerator based on the Coulomb barrier for single-electron tunneling. A fully normal single-electron transistor is voltage V biased at a gate position such that tunneling through one of the junctions costs an energy of about kBTâ‰eV,EC, where T is the temperature and EC is the transistor charging energy. The tunneling in the junction with positive energy cost cools both leads attached to it. Immediate practical realizations of such a refrigerator make use of Andreev mirrors which suppress heat current while maintaining full electric contact.