Excitonic entanglement of protected states in quantum dot molecules

Abstract

The entanglement of an optically generated electron-hole pair in artificial quantum dot molecules is calculated considering the effects of decoherence by interaction with environment. Since the system evolves into a mixed states and due to the complexity of energy level structure, we use the negativity as entanglement quantifier, which is well defined in $d\otimes d^{\prime }$ composite vector spaces. By a numerical analysis of the non-unitary dynamics of the exciton states, we establish the feasibility of producing protected entangled superpositions by an appropriate tuning of bias electric field, $F$. A stationary state with a high value of negativity (high degree of entanglement) is obtained by fine tuning of $F$ close to a resonant condition between indirect excitons. We also found that when the optical excitation is set approximately equal to the electron tunneling coupling, $\Omega /T_e\sim 1$, the entanglement reaches a maximum value. In front of the experimental feasibility of the specific condition mentioned before, our proposal becomes an useful strategy to find robust entangled states in condensed matter systems.

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References in corpus (6)

• Direct measurement of finite-time disentanglement induced by a reservoir
• Scalable qubit architecture based on holes in quantum dot molecules
• Robust states in semiconductor quantum dot molecules
• Creating excitonic entanglement in quantum dots through the optical Stark effect
• Steady state entanglement of two coupled qubits
• Forster energy transfer signatures in optically driven quantum dot molecules

Cited by in corpus (3)

• Attractive dipolar coupling between stacked exciton fluids
• Quantum entanglement driven by electron-vibrational mode coupling
• Dynamic generation of GHZ states with coupled charge qubits