Tunnelling spectroscopy of gate-induced superconductivity in MoS2

The ability to gate-induce superconductivity by electrostatic charge accumulation is a recent breakthrough in physics and nanoelectronics. With the exception of LaAlO 3 /SrTiO 3 interfaces, experiments on gate-induced superconductors have been largely confined to resistance measurements, which provide very limited information about the superconducting state. Here, we explore gate-induced superconductivity in MoS 2 by performing tunnelling spectroscopy to determine the energy-dependent density of states (DOS) for different levels of electron density n . In the superconducting state, the DOS is strongly suppressed at energy smaller than the gap Δ , which is maximum ( Δ ~2 meV) for n of ~1 × 10 14 cm −2 and decreases monotonously for larger n . A perpendicular magnetic field B generates states at E