Entanglement and quantum phase transition of spin glass: A renormalization group approach

Using a renormalization group approach, we study the entanglement properties of two spin glass models: the XXZ Heisenberg (with Dzyaloshinskii–Moriya interaction) and Ising transverse field spin glasses. The concurrence for both models are obtained through the Kadanoff renormalization group (RG) approach with random J_i^z and J_i respectively. The constant couplings in the RG flow are randomized through the Gaussian distribution. For Δ=0 corresponding to a non-spin glass material, a first-order transition is expected. By varying Δ from 0.05 to 0.5, the spin glass effect broadens the sharp transition resulting in a second-order-like transition. The fluctuations in the average concurrence for the spin glass case as measured by the standard deviations is also a good indicator of quantum phase transition. - Highlights: • Concurrence for two spin glass models are obtained by Kadanoff renormalization group approach. • For Δ=0, a first-order phase transition is expected. • By varying Δ from 0.05 to 0.5, the spin glass effect broadens the sharp transition. • The spin glass effect causes a change in first-order to second-order transition. • Fluctuations in the average concurrence for spin glass is a good indicator of quantum phase transition