2025/09/01 by Hana Vargová, Jozef Strečka, Vargová, Hana +1
Materials Science · Chemistry · #Magnetism in coordination complexes #Advanced NMR Techniques and Applications #Advanced Physical and Chemical Molecular Interactions
paper · pdf · doi:10.48550/arxiv.2509.01451
The effect of uniaxial single-ion anisotropy on quantum entanglement is rigorously quantified using negativity in a mixed spin-(1,1/2,1) Heisenberg trimer, accounting for different exchange coupling constants between identical and distinct spins. Bipartite negativities between the single-spin entity and the remaining spin dimer are analyzed alongside the global tripartite negativity (gTN) of the whole trimer under the effect of an external magnetic field and both easy-axis and easy-plane types of single-ion anisotropy. Interestingly, the single-ion anisotropy significantly influences the degree of entanglement by altering the stability regions of energetically preferred ground states and it may also introduce additional phases in the overall ground-state phase diagram. Moreover, it is demonstrated that within specific ground states, the degree of entanglement primarily depends on the strength of single-ion anisotropy, altering the respective probability amplitudes of the corresponding eigenvectors. Finally, the thermal stability of entanglement is discussed in detail, including the emergence of a peculiar local minimum at finite temperatures. The obtained theoretical results may offer deeper insights into bipartite and tripartite entanglement in trimetallic Ni2+-Cu2+-Ni2+ molecular compounds.