Random Bonds and Topological Stability in Gapped Quantum Spin Chains
Random Bonds and Topological Stability in Gapped Quantum Spin Chains
Using an asymptotically exact real space renormalization procedure, we find that the dimerized spin-1/2 chain is extremely stable against bond randomness. For weak dimerization or, equivalently, strong randomness, it is in a Griffiths phase with short-range spin-spin correlations and a divergent susceptibility. The string topological order persists. We conjecture that …