Zakaria Bouafia | Searcharxiv

arXiv2026

Quantum Steering and Nonlocal Correlations Between Non-Interacting Delocalized Electrons Under Rashba Spin-Orbit Interaction

We investigate quantum steering and nonlocal correlations between two electrons in a two-dimensional electron gas (2DEG) as functions of Rashba spin-orbit interaction (RSOI) strength and inter-electron separation. We focus particularly on the Bi/Ag(111) system characterized by its strong RSOI ($α_0 = 3.05\times10^{-11}$ eV~m), and we explore the influence of tuning intensity of RSOI and inter-electron distance on the dynamics of Bell nonlocality, uncertainty-induced nonlocality and steering. We find that, although increasing $α_R$ initially suppresses quantum correlations, all three metrics exhibit a non-monotonic recovery as functions of $α_R$, peaking near an optimal coupling strength $α_R = 4.32\times10^{-11}$~eV~m across the range of inter-electron separations considered. This finding establishes RSOI as a critical control parameter for stabilizing quantum properties in two-dimensional electron gases against the decay of quantum correlations with inter-electron separation, and shows that the suppression and recovery of quantum resources within the Bi/Ag(111) system can be controlled by adjusting the inter-electron distance and carefully tuning the RSOI strength.

quant-ph↗

arXiv2026

Basis-independent coherence and quantum correlations in two dipole-dipole-coupled electrons in double quantum-dot molecules

This work examines the thermal dynamics of basis-independent quantum coherence and correlation-based quantum resources for two dipole-dipole-coupled electrons confined in spatially separated quantum-dot (QD) molecules. Single-dot quantum superpositions and inter-subsystem coherence are characterized by using localized and collective coherence. Quantum correlations between the two double quantum dots are quantified by employing Bures distance entanglement, Local quantum uncertainty (LQU), and local quantum Fisher Information (LQFI). The findings show that dipole-dipole coupling $K$ is the most effective protective parameter, extending the entanglement sudden death temperature, diminishing the local quantum superpositions and enhancing the collective coherence. The dipole-dipole interaction has also a crucial impact on protecting LQU and LQFI beyond the entanglement sudden death temperature. Coulomb repulsion $J$ reinforces this protection through an independent channel, projecting the thermal state onto the entangled $\{|0_A 1_B\rangle,|1_A 0_B\rangle\}$ subspace; their combined action is required to approach the entanglement maximum, and it enhances collective coherence and extends the temperature range over which LQU and LQFI remain appreciable. Energy detuning $\varepsilon$ can enhance localized coherence but paradoxically accelerates the entanglement sudden death and quenches LQU and LQFI by weakening two-body correlations. Inter-dot tunneling $Γ$ enhances local superpositions at low temperature, but it reduces collective coherence, lowers the entanglement sudden death temperature, and disrupts other nonclassical correlations.

quant-ph↗