  We propose a method to construct a classical analog of an open quantum
system, namely a single quantum particle confined in a potential well and
immersed in a thermal bath. The classical analog is made out of a collection of
identical wells where classical particles of mass $m$ are trapped. The
distribution $n(x,t)$ of the classical positions is used to reconstruct the
quantum Bohm potential $V_{\rm Bohm} = -\frac{\hbar^2}{2 m} \frac{\Delta
\sqrt{n}}{\sqrt{n}}$, which in turn acts on the shape of the potential wells.
As a result, the classical particles experience an effective "quantum" force.
This protocol is tested with numerical simulations using single- and
double-well potentials, evidencing typical quantum effects such as long-lasting
correlations and quantum tunneling. For harmonic confinement, the analogy is
implemented experimentally using micron-sized dielectric beads optically
trapped by a laser beam.
