Abstract Recently, Ming et al (Quantum Inf Process 17 267, 2018) have investigated the entropic uncertainty relation in the presence of quantum memory (EUR-QM) and quantum coherence in a thermal regime for a two-spin chain under the effect of Dzyaloshinskii–Moriya (DM) interaction. Here, we study thermal quantum coherence and EUR-QM for a three-spin chain in Ising model under the effect of different directions of DM interaction. Our results confirm the results for the two-qubit case. Increasing temperature can reduce the quantum coherence but oppositely the uncertainty will grow. We show that the coupling parameter and DM interaction have constructive effects on quantum coherence and they reduce uncertainty in measurement results of incompatible observables, and especially the y -direction of DM interaction has a better influence on decreasing the uncertainty than the x and z directions. Unfortunately, the effect of the third spin acts destructively on the uncertainty and its bound, as well as the quantum coherence between the first two spins. Notably, an explicit relationship between quantum coherence and the uncertainty lower bound is found.
Abstract Recently, Ming et al (Quantum Inf Process 17 267, 2018) have investigated the entropic uncertainty relation in the presence of quantum memory (EUR-QM) and quantum coherence in a thermal regime for a two-spin chain under the effect of Dzyaloshinskii–Moriya (DM) interaction. Here, we study thermal quantum coherence and EUR-QM for a three-spin chain in Ising model under the effect of different directions of DM interaction. Our results confirm the results for the two-qubit case. Increasing temperature can reduce the quantum coherence but oppositely the uncertainty will grow. We show that the coupling parameter and DM interaction have constructive effects on quantum coherence and they reduce uncertainty in measurement results of incompatible observables, and especially the y -direction of DM interaction has a better influence on decreasing the uncertainty than the x and z directions. Unfortunately, the effect of the third spin acts destructively on the uncertainty and its bound, as well as the quantum coherence between the first two spins. Notably, an explicit relationship between quantum coherence and the uncertainty lower bound is found.
Abstract In this article, we investigate the dynamics and correlations of quantum-memory-assisted entropic uncertainty, the tightness of the uncertainty, entanglement, quantum correlation and mixedness for various spin chain models with Dzyaloshinskii–Moriya (DM) interaction, including the XXZ model with DM interaction, the XY model with DM interaction and the Ising model with DM interaction. We find that the uncertainty grows to a stable value with growing temperature but reduces as the coupling coefficient, anisotropy parameter and DM values increase. It is found that the entropic uncertainty is closely correlated with the mixedness of the system. The increasing quantum correlation can result in a decrease in the uncertainty, and the robustness of quantum correlation is better than entanglement since entanglement means sudden birth and death. The tightness of the uncertainty drops to zero, apart from slight volatility as various parameters increase. Furthermore, we propose an effective approach to steering the uncertainty by weak measurement reversal.
Abstract In this paper, we have investigated the dynamical features of tripartite quantum-memory-assisted entropic uncertainty (tQMA-EU) and its two corresponding lower bounds in three-qubit Heisenberg XXZ spin chain model with Dzyaloshinskii-Moriya (DM) interaction and Kaplan-Shekhtman-Entin-Wohlman-Aharony (KSEA) interaction. The results show that, when the DM and KSEA interaction are taken account, the Dolatkhah's lower bound is always equal to the tQMA-EU and remains higher than the Ming's lower bound in both ferromagnetic and antiferromagnetic cases.The increasing of DM and KASE interactions can effectively reduce the value of tQMA-EU, the varying behaviors of tQMA-EU with respect to DM and KASE interactions from positive and negative intervals demonstrate central symmetry. Particularly, in ferromagnetic case, this reduction effect is more pronounced than that in antiferromagnetic case. In addition, the dynamical features of Dolatkhah's lower bound and Ming's lower bound with respect to the spin chain systemic parameters display distinct differences in the ferromagnetic and antiferromagnetic cases. Specifically, in the ferromagnetic case and with weak DM interaction, during the lower temperature range, under the influence of the KSEA interaction and under an external magnetic field, the Dolatkhah's lower bound dosen't negative-correlated to tripartite negativity quantum correlation N ABC . in contrast, the dynamics of Ming's lower bound show negative-correlated to N ABC .
In this paper, we study the thermal dynamics of quantum correlations and uncertainty relation in a three-qubit spin chain under the effect of Hamiltonian XY model, Dzyaloshinskii–Moriya (DM) interaction and external magnetic field. The results show that quantum correlations behave contrary to uncertainty under the effect of thermal dynamics and external magnetic field. However, they evolve in the same way under effect of DM interaction and spin coupling. DM interaction, magnetic field and spin coupling enhance quantum correlations.
-axis, the current study explores the quantum-memory-assisted entropic uncertainty relation (QMA-EUR), entropy mixedness and the concurrence two-spin entanglement. Quantum entanglement is reduced at increased temperature values, but inflation uncertainty and mixedness are enhanced. The considered quantum effects are stabilized to their stationary values at high temperatures. The two-spin entanglement is entirely repressed if the D-M interaction is disregarded, and the entropic uncertainty and entropy mixedness reach their maximum values for equal coupling rates. Rather than the concurrence, the entropy mixedness can be a proper indicator of the nature of the entropic uncertainty. The effect of model parameters (D-M coupling and dipole-dipole spin) on the quantum dynamic effects in thermal environment temperature is explored. The results reveal that the model parameters cause significant variations in the predicted QMA-EUR.
Abstract In this study, the quantum-memory assisted entropic uncertainty (QM-EU) and entanglement dynamics of the two-qubit Heisenberg XXX chain have been explored in the presence of intrinsic decoherence. The effect of the x-component of Dzyaloshinskii-Moriya (DM) and Kaplan-Shekhtman-Entin-Wohlman-Aharony (KSEA) interactions has been considered. The generation and preservation of quantum memory and entanglement have been examined for various values of the DM, KSEA, spin-spin, and spin coupling strengths. The uncertainty negatively affects the entanglement and both have anti-correlation. The absence and presence of intrinsic decoherence prevail in differing impacts on the dynamics of the system. In the first case, prolonged entanglement preservation, uncertainty suppression, and oscillatory dynamics have been observed. Moreover, in order to achieve the best-prolonged entanglement preservation and relative reduction of the entropic uncertainty, we have analyzed several parameter settings. We find that the effects of raising the DM, KSEA, and spin-spin interaction individually and simultaneously are different. The individual and simultaneous increase of the DM, KSEA, and spin-spin interaction parameters control the degree of entanglement, entropic uncertainty, and primarily the dynamics of the system.
Abstract We investigate the quantum-memory-assisted entropic uncertainty relation (QMA-EUR) in a Heisenberg XYZ mixed-spin (1/2, 1) model. Coupling strength, Dzyaloshinskii–Moriya (DM) interaction and inhomogeneous magnetic field, respectively, contributing to QMA-EUR by a thermal entanglement in the hybrid-spin model are studied in detail. Furthermore, we compare the uncertainty of the bipartite hybrid model with those of qubit–qubit and qutrit–qutrit systems. Meanwhile, the effects of local PT-symmetric operation and weak measurement on the steering of entropic uncertainty are analyzed. We find that the local PT-symmetric operation can reduce the entropic uncertainty, and the entropic uncertainty can also be decreased by weak measurement reversal.