1211.3865 (N. Amiri et al.)

Quantum critical phase diagram of bond alternating Ising model with
Dzyaloshinskii-Moriya interaction: signature of ground state fidelity    [PDF]

N. Amiri, A. Langari

We present the zero temperature phase diagram of the bond alternating Ising chain in the presence of Dzyaloshinskii-Moriya interaction. An abrupt change in ground state fidelity is a signature of quantum phase transition. We obtain the renormalization of fidelity in terms of quantum renormalization group without the need to know the ground state. We calculate the fidelity susceptibility and its scaling behavior close to quantum critical point (QCP) to find the critical exponent which governs the divergence of correlation length. The model consists of a long range antiferromagnetic order with nonzero staggered magnetization which is separated from a helical ordered phase at QCP. Our results state that the critical exponent is independent of the bond alternation parameter (lambda) while the maximum attainable helical order depends on lambda.

View original: http://arxiv.org/abs/1211.3865