  We propose a density matrix renormalization group (DMRG) technique at finite
temperatures. As is the case of the ground state DMRG, we use a single-target
state that is calculated by making use of a regulated polynomial expansion.
Both static and dynamical quantities are obtained after a random-sampling and
averaging procedure. We apply this technique to the one-dimensional Hubbard
model at half filling and find that this gives excellent results at low
temperatures.
