Thermodynamic Properties and Decoherence of a Central Electron Spin of Atom Coupled to an Anti-Ferromagnetic Spin Bath

Abstract

<p> <span>The decoherence of a central electron spin of an atom coupled to an anti-ferromagnetic spin bath in the presence of a time varying B-Field (VBF) is investigated applying the Holstein</span><span>-</span><span>Primak</span><span> </span><span>o</span><span>ff</span><span> and Bloch transformations approaches. The Boltzmann entropy and the specific heat capacity at a given temperature are obtained and show the correlation of the coupling of the spin bath and the electron spin of the central atom. At low frequencies the coherence of the coupled system is dominated by the magnetic field intensity. At low VBF intensity, there is decrease in entropy and heat capacity at increase external magnetic field that show the decoherence suppression of the central electron spin atom. The crossing observed in the specific heat capacity corresponds to the critical field point <i>Bc</i> of the system which represents the point of transition from the anti-ferromagnetic system to the ferromagnetic one.</span><span></span> </p

Dzyaloshinskii–Moriya interaction effects on the entanglement dynamics of a two qubit XXZ spin system in non-Markovian environment

“…[27] the study made on the dynamics of a single spin in a spin star environment, using exact methods and various approximation techniques, reveal that the Markovian approximations perform poorly. In this paper, we study analytically and numerically the exact entanglement dynamics of a two qubit Heisenberg XXZ spin chain with DM interactions interacting with a spin bath in the presence of an external magnetic field using a simple mathematical technique based on a unitary linear transformation [28,29]. We examine the effects of the external magnetic field strength, temperature, intra-bath coupling strength, system bath coupling and anisotropy of the two qubit spin chain, on the entanglement dynamics, considering the interactions of the qubit systems with the environment.…”

Tailoring Quantum Correlations of a Coupled Central Two Qubits Soaked in a Finite Temperature Antiferromagnetic Environment with Frequency Gap

“…The spin structure of the environment is taken to be divided into two interpenetrating sub-lattices a and b with gap in its frequency spectrum. This investigation is an extension of our recent works where the dynamics of a single qubit was considered [11]- [13].…”

Entanglement Dynamics of Random GUE Hamiltonians

“…For example, this is realized in central-spin type models whose Hamiltonians H CS = k J k S 0 I k describe interaction between a "central spin" S 0 and the nuclear spins I k with arbitrarily distributed couplings J k . This Hamiltonian, while integrable for arbitrary J k 's, is used to model quantum dots and NV centers [29,30] reduced BCS models and Dicke-type systems [31]. These integrable models represent a subclass of more elaborate non-integrable counterparts which can be used to describe more realistic setups [32].…”