Density matrix renormalization group method for random quantum one-dimensional systems - Application to the random spin-1/2 antiferromagnetic Heisenberg chain

The density matrix renormalization group method is generalized to one-dimensional random systems. Using this method, the energy gap distribution of the spin-1/2 random antiferromagnetic Heisenberg chain is calculated. The results are consistent with the predictions of the renormalization group theory demonstrating the effectiveness of the present method in random systems. The possible application of the present method to other random systems is discussed.