Quantum interference in the time-of-flight distribution

We propose a scheme to experimentally observe matter-wave interference in the time domain, specifically in the arrival time or time-of-flight (TOF) distribution for an atomic Bose-Einstein condensate (BEC) Schrödinger-cat state represented by superposition of macroscopically separated wave packets in space. This is in contrast to interference in space at a fixed time observed in the reported BEC experiments. We predict and quantify the quantum interference in the TOF distribution calculated from the modulus of the quantum probability current density (rather than the TOF distributions obtained from a purely classical or semi-classical treatment in many reported experiments). The interference and hence the coherence in the quantum TOF signal disappears in the large-mass limit. Our scheme has the potential to probe the validity of various other theoretical approaches (Muga and Leavens 2000 Phys. Rep. 338 353) of calculating the quantum arrival time distribution.