Thermal quantum correlations in a two-dimensional spin star model

Abstract

In this paper, we study the thermal evolution of three types of quantum correlations under the homogeneous and inhomogeneous spin star Hamiltonian. It is shown that quantum discord (QD) is more stable than the other measures in the thermal regime, but concurrence is more efficient when the Hamiltonian parameters are employed. However, all quantum correlations can reach their maximum, if the inhomogeneous parameter raises. Quantum correlations can be enhanced by a weak external magnetic field and strong coupling parameter. But they vanish in the case of a strong magnetic field, weak coupling parameter, and high temperatures.

Spin‐Chain‐Star Systems: Entangling Multiple Chains of Spin Qubits

“…The interest towards central spin models has remarkably grown thanks to: I) their suitability in describing the hyperfine interaction in quantum dots [27] and the interactions between nuclear spins and nitrogen-vacancy centers in diamond [28,29] ; II) their broad applicability in different fields like quantum information, [30] quantum metrology and sensing, [31,32] quantum thermodynamics [33] and fundamental aspects. [34] Further, a lots of works have been developed to investigate the quantum correlation and thermal entanglement arising among spins in the star framework, [35][36][37][38][39] as well as the Markovian and non-Markovian dynamics induced by a surrounding bath interacting with the spinstar system. [40][41][42] Recently, the idea of spin-chain-star system has been proposed [43,44] where the control spin occupies the center of a star of M rays (chains), arranged at angular distance 2𝜋∕M, each of which hosts the same sequence of N spins, generally equidistant.…”

Spin-chain-star systems: entangling multiple chains of spin qubits

“…The interest towards central spin models has remarkably grown thanks to: I) their suitability in describing the hyperfine interaction in quantum dots [27] and the interactions between nuclear spins and nitrogen-vacancy centers in diamond [28,29]; II) their broad applicability in different fields like quantum information [30], quantum metrology and sensing [31,32], quantum thermodynamics [33] and fundamental aspects [34].Further, a lots of works have been developed to investigate the quantum correlation and thermal entanglement arising among spins in the star framework [35][36][37][38][39], as well as the Markovian and non-Markovian dynamics induced by a surrounding bath interacting with the spin-star system [40][41][42].…”

Suppressing measurement uncertainty in an inhomogeneous spin star system

“…Moreover, Militello and Messina 94 examined the tripartite thermal entanglement in an inhomogeneous spin-star network with three external spins. From a practical point of view, the spin-star system can be realized in many solid state systems, such as the nitrogen-vacancy centre in diamond 97 , 98 and the semiconductor quantum dot 99 – 101 (see recent paper 102 and references therein for a detailed study on the spin-star system). However, to the best of our knowledge, nobody has previously examined the entropic uncertainty for a spin-star system up to now.…”