  We consider an overdamped nanoparticle in a driven double-well potential as a
generic model of an erasable one-bit memory. We study in detail the statistics
of the heat dissipated during an erasure process and show that full erasure may
be achieved by dissipating less heat than the Landauer bound. We quantify the
occurrence of such events and propose a single-particle experiment to verify
our predictions. Our results show that Landauer's principle has to be
generalized at the nanoscale to accommodate heat fluctuations.
