  In modern computers, computation is performed by assembling together sets of
logic gates. Popular gates like AND, OR, XOR, processing two logic inputs and
yielding one logic output, are often addressed as irreversible logic gates
where the sole knowledge of the output logic value, is not sufficient to infer
the logic value of the two inputs. Such gates are usually believed to be
bounded to dissipate a finite minimum amount of energy determined by the
input-output information difference. Here we show that this is not necessarily
the case, by presenting an experiment where a OR logic gate, realized with a
micro electromechanical cantilever, is operated with energy well below the
expected limit, provided the operation is slow enough and frictional phenomena
are properly addressed.
