  In this paper we first show that dynamic switching schemes can be used to
reduce energy dissipation below the thermodynamic minimum of NkTlnr (N= number
of state variables, 1/r=error probability), but only at the expense of the
error immunity inherent in thermodynamic processes for which the final state is
insensitive to the switching dynamics. It is further shown that, for a system
which has internal feedback, e.g. nanomagnets, such that all N spins act in
concert, it should be possible to switch with an energy dissipation of the
order of kTlnr (considerably less than the thermodynamic limit of NkTlnr),
while retaining an error immunity comparable to thermodynamic switching.
