Thermal entanglement in ferrimagnetic chains
Xiaoguang Wang, Z. D. Wang · Physical Review A · 2006
A formula to evaluate the entanglement in a one-dimensional ferrimagnetic system is derived. Based on the formula, we find that the thermal entanglement in a small size spin-$1∕2$ and spin-$s$ ferrimagnetic chain is rather robust against temperature, and the threshold temperature may be arbitrarily high when $s$ is sufficiently large. This intriguing result answers unambiguously a fundamental question: ``Can entanglement and quantum behavior in physical systems survive at arbitrary high temperatures?''