Non-local electrostatic gating in Majorana nanowires

Ever since the predicted existence of Majorana Zero-Modes (MZMs), the building blocks of topological quantum computation in hybrid semiconductor-superconductor wires, experimental efforts to detect signatures of MZMs have mainly focused on tunneling experiments, culminating in the recent observation of quantized Majorana conductance. However, the local probes used in previous studies cannot unambiguously reveal the non-local separation of MZMs, the hallmark of topological superconductivity. Here we study non-local properties of MZMs in tunneling spectroscopy on InSb nanowires covered with epitaxial aluminium by using two separate gates underneath the superconductor, one to tune part of the wire into the topological phase and an additional remote gate to tune the potential at the far end of the topological section. By tuning the remote gate we observe zero-bias peak splitting in the local tunneling measurement, presumably due to variation in the overlap between MZMs at the two ends. In contrast, trivial Andreev Bounds States, identified by instability with respect to the local gates, are completely insensitive to the remote gate.