  Landauer principle states that erasure of $N$ bit information requires an
entropic cost of $Nk_B \ln 2$. This fact can easily be demonstrated by
relaxation of an ideal gas consisting of $N$ particles inside a fixed volume.
In this paper we discuss the modification of Landauer bound when we use
non-ideal gas with inter-particle interactions for erasure procedure. We have
found that the bound on the entropy production can be lowered when the
interaction between particles is square-well potential.
