caa a22 4500 44588648X CHVBK 20180317145601.0 cr unu---uuuuu 170323e20110601xx s 000 0 eng 10.1007/s11128-010-0198-6 doi (NATIONALLICENCE)springer-10.1007/s11128-010-0198-6 Entanglement of dipolar coupling spins [Elektronische Daten] [G. Furman, V. Meerovich, V. Sokolovsky] Entanglement of dipole-dipole interacting spins 1/2 is usually investigated when the energy of interaction with an external magnetic field (the Zeeman energy) is greater than the energy of dipole interactions by three orders. Under this condition only a non-equilibrium state of the spin system, realized by pulse radiofrequence irradiations, results in entanglement. The present paper deals with the opposite case: the dipolar interaction energy is the order of magnitude or even larger than the Zeeman one. It was shown that entanglement appears under the thermodynamic equilibrium conditions and the concurrence reaches the maximum when the external field is directed perpendicular to the vector connecting the nuclei. For this direction of the field and a system of two spins with the Hamiltonian accounting the realistic dipole-dipole interactions in low external magnetic field, the exact analytical expression for concurrence was also obtained. The condition of the entanglement appearance and the dependence of concurrence on the external magnetic field, temperature, and dipolar coupling constant were studied. Springer Science+Business Media, LLC, 2010 Dipolar interaction nationallicence Entanglement nationallicence Spin system nationallicence Furman G. Department of Physics, Ben-Gurion University of the Negev, POB 653, 84105, Beer-Sheva, Israel aut Meerovich V. Department of Physics, Ben-Gurion University of the Negev, POB 653, 84105, Beer-Sheva, Israel aut Sokolovsky V. Department of Physics, Ben-Gurion University of the Negev, POB 653, 84105, Beer-Sheva, Israel aut Quantum Information Processing Springer US; http://www.springer-ny.com 10/3(2011-06-01), 307-315 1570-0755 10:3<307 2011 10 11128 https://doi.org/10.1007/s11128-010-0198-6 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11128-010-0198-6 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Furman G. Department of Physics, Ben-Gurion University of the Negev, POB 653, 84105, Beer-Sheva, Israel aut NATIONALLICENCE 700 1- Meerovich V. Department of Physics, Ben-Gurion University of the Negev, POB 653, 84105, Beer-Sheva, Israel aut NATIONALLICENCE 700 1- Sokolovsky V. Department of Physics, Ben-Gurion University of the Negev, POB 653, 84105, Beer-Sheva, Israel aut NATIONALLICENCE 773 0- Quantum Information Processing Springer US; http://www.springer-ny.com 10/3(2011-06-01), 307-315 1570-0755 10:3<307 2011 10 11128 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer