Quantum correlations and coherence in a mixed spin- (12,1) Heisenberg dimer under intrinsic decoherence

Abstract

This research delves into the dynamical behavior of quantum correlations and coherence within a mixed Heisenberg dimer system under the intrinsic decoherence. Our approach involves the application of logarithmic negativity, local quantum uncertainty, and the ℓ 1 norm-based coherence as quantifiers for entanglement, skew information correlations, and quantum coherence in this qubit-qutrit model. Our primary objective is to explore the impact of various factors on the dynamics of quantum correlations and quantum coherence. These factors encompass the initial density matrix and its mixing parameter, the intrinsic decoherence rate (γ), the external magnetic field, as well as intrinsic system parameters, notably the XXZ and uniaxial single-ion anisotropies. Our results demonstrate that the introduction of intrinsic decoherence (ID) significantly erodes quantum resources. Particularly, for high values of the ID rate (γ), excessive damping occurs, leading to the absence of oscillations or a rapid decay of quantum resources, ultimately stabilizing in steady states. Furthermore, the presence of an external homogeneous magnetic field further diminishes quantum resources within the system. However, despite the degradation induced by the combined influence of intrinsic decoherence and high external magnetic field intensities, the judicious selection of the initial density matrix and precise adjustment of the uniaxial single-ion anisotropy enable the preservation of quantum resources within the mixed spin-(1/2, 1) Heisenberg dimer.

Room-Temperature Entanglement of the Nickel-Radical Molecular Complex (Et3NH)[Ni(hfac)2L] Reinforced by the Magnetic Field

“…One possible route towards a physical realization of the molecular qubit is offered by heterobimetallic dinuclear complexes, which represent paradigmatic realizations of the mixed spin-( 12 , S) Heisenberg dimer with an antiferromagnetic exchange interaction. For this reason, the mixed spin-( 12 , 1) Heisenberg dimer has recently attracted considerable attention as the simplest member of this class of quantum spin models [27][28][29][30][31][32][33][34][35]. Among other matters, it has been evidenced that the mixed spin-( 12 , 1) Heisenberg dimer has a higher threshold temperature for thermal entanglement compared with the pure spin- 1 2 Heisenberg dimer [27], the strength of thermal entanglement is significantly influenced by a nonuniform magnetic field resulting from different g-factors of individual metal centers [28,29], the Zeeman's splitting of energy levels may substantially enhance the strength of thermal entanglement at low magnetic fields [30][31][32], the electric field can serve as another driving force controlling the strength of thermal entanglement [33], and the thermal entanglement can be quite robust against decoherence [34,35].…”

“…For this reason, the mixed spin-( 12 , 1) Heisenberg dimer has recently attracted considerable attention as the simplest member of this class of quantum spin models [27][28][29][30][31][32][33][34][35]. Among other matters, it has been evidenced that the mixed spin-( 12 , 1) Heisenberg dimer has a higher threshold temperature for thermal entanglement compared with the pure spin- 1 2 Heisenberg dimer [27], the strength of thermal entanglement is significantly influenced by a nonuniform magnetic field resulting from different g-factors of individual metal centers [28,29], the Zeeman's splitting of energy levels may substantially enhance the strength of thermal entanglement at low magnetic fields [30][31][32], the electric field can serve as another driving force controlling the strength of thermal entanglement [33], and the thermal entanglement can be quite robust against decoherence [34,35]. From a materials science perspective, the thermal entanglement of experimental realizations of the antiferromagnetic mixed spin-( 12 , 1) Heisenberg dimer has been studied only for the particular case of the heterodinuclear complex [36], which exhibits thermal entanglement up to a threshold temperature of about 140 K, comparable to the magnitude of the exchange coupling constant between the spin-1 2 Cu 2+ and spin-1 Ni 2+ magnetic ions [30,32].…”