Thermodynamic density matrix renormalization group study of the magnetic susceptibility of half-integer quantum spin chains

It is shown that White's density matrix renormalization group technique can be adapted to obtain thermodynamic quantities. As an illustration, the magnetic susceptibility of Heisenberg S = 1/2 and S = 3/2 spin chains are computed. A careful finite size analysis is made to determine the range of temperatures where the results are reliable. For the S = 1/2 chain, the comparison with the exact Bethe ansatz curve shows an agreement within 1% down to T = 0.05J.