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 techniqu e can be adapted to obtain thermodynamic quantities. As an illustratio n, the magnetic susceptibility of Heisenberg S = 1/2 and S = 3/2 spin chains are computed. A careful finite size analysis is made to determi ne the range of temperatures where the results are reliable. For the S = 1/2 chain, the comparison with the exact Bethe ansatz curve shows a n agreement within 1% down to T = 0.05J.