Interplay of Bipartite Entanglement between Two Geometrically Inequivalent Spin Pairs of a Spin-1/2 Heisenberg Distorted Tetrahedron |
| K. Karľová, J. Strečka
Faculty of Science, P.J. Šafárik University, Park Angelinum 9, 04001 Košice, Slovakia |
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| The energy spectrum, ground-state phase diagram, pair correlation functions, and concurrence are exactly calculated for a spin-1/2 quantum Heisenberg distorted tetrahedron in a magnetic field. The ground-state phase diagram in the interaction ratio versus magnetic field plane totally involves five different ground states, which differ from one another by the total spin, local pair correlation functions, and/or concurrence. In addition to the classical fully polarized ferromagnetic ground state there also appear four outstanding quantum ground states, two of which belong to a singlet sector and another two to a triplet sector. A degree of bipartite entanglement quantified through the concurrence is examined as a function of magnetic field, temperature, and the interaction ratio. |
DOI:10.12693/APhysPolA.137.595 topics: Heisenberg model, distorted tetrahedron, entanglement, concurrence |