Thermal entanglement in a spin-1/2 Ising-XYZ distorted diamond chain with the second-neighbor interaction between nodal Ising spins

摘要

We consider a spin-1/2 Ising-XYZ distorted diamond chain with the XYZinteraction between the interstitial Heisenberg dimers, the nearest-neighborIsing coupling between the nodal and interstitial spins, respectively, and thesecond-neighbor Ising coupling between the nodal spins. The ground-state phasediagram of the spin-1/2 Ising-XYZ distorted diamond chain exhibits severalintriguing phases due to the XY anisotropy and the second-neighbor interaction,whereas the model can be exactly solved using the transfer-matrix technique.The quantum entanglement within the Heisenberg spin dimers is studied through abipartite measure concurrence, which is calculated from a relevant reduceddensity operator. The concurrence may either show a standard thermal dependencewith a monotonous decline with increasing temperature or a more peculiarthermal dependence accompanied with reentrant behavior of the concurrence. Itis conjectured that the bipartite entanglement between the interstitialHeisenberg spin pairs in the natural mineral azurite is quite insensitive tothe applied magnetic field and it persists up to approximately 30 Kelvins.