Tosson Elalaily † , ‡ , Olivér Kürtössy † , Zoltán Scherübl † , ¶ , Martin Berke † , Gergö Fülöp † , István Endre Lukács ⊥ , Thomas Kanne # , Jesper Nygård # , Kenji Watanabe ∇ , Takashi Taniguchi ○ , Péter Makk † , , Szabolcs Csonka † ,
02 November 2021
Gate-controlled supercurrent (GCS) in superconducting nanobridges has recently attracted attention as a means to create superconducting switches. Despite the clear advantages for applications, the microscopic mechanism of this effect is still under debate. In this work, we realize GCS for the first time in a highly crystalline superconductor epitaxially grown on an InAs nanowire. We show that the supercurrent in the epitaxial Al layer can be switched to the normal state by applying ≃±23 V on a bottom gate insulated from the nanowire by a crystalline hBN layer. Our extensive study of the temperature and magnetic field dependencies suggests that the electric field is unlikely to be the origin of GCS in our device. Though hot electron injection alone cannot explain our experimental findings, a very recent non-equilibrium phonons based picture is compatible with most of our results.