Low-temperature density matrix renormalization group using regulated polynomial expansion

Understand

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.