Entanglement and the interplay between staggered fields and couplings

Jenny Hide, Yoshifumi Nakata, Mio Murao
2012 Physical Review A. Atomic, Molecular, and Optical Physics  
We investigate how the interplay between a staggered magnetic field and staggered coupling strength affects both ground state and thermal entanglement. Upon analytically calculating thermodynamic quantities and the correlation functions for such a system, we consider both the global Meyer-Wallach measure of entanglement and the concurrence between pairs of spins. We discover two quantum phase transitions present in the model and show that the quantum phase transitions are reflected in the
more » ... our of the entanglement at zero temperature. We discover that increasing the alternating field and alternating coupling strength can actually increase the amount of entanglement present at both zero temperature and for thermal states of the system.
doi:10.1103/physreva.85.042303 fatcat:w55mm3adqrbczoknww7yx3gfaa