Anomalous photon-assisted tunneling in periodically driven Majorana nanowires and BCS charge measurement

The photon-assisted tunneling of Majorana bound states in a Majorana nanowire driven by the periodic field is studied both theoretically and numerically. We find that Majorana bound states exhibit an anomalous photon-assisted tunneling signal, which is different from an ordinary fermionic state: the height of photonic sidebands is related to the degree of Majorana nonlocality. Moreover, we show that the Bardeen---Cooper---Schrieffer (BCS) charge and spin components of subgap states can be well revealed by the local conductance. Our work illuminates the effect of driving field on Majorana bound states and provides a systematic scheme to directly measure BCS information of overlapping Majorana bound states.