Limitation of entanglement due to spatial qubit separation

Abstract

We consider spatially separated qubits coupled to a thermal bosonic field that causes pure dephasing. Our focus is on the entanglement of two Bell states which for vanishing separation are known as robust and fragile entangled states. The reduced two-qubit dynamics is solved exactly and explicitly. Our results allow us to gain information about the robustness of two-qubit decoherence-free subspaces with respect to physical parameters such as temperature, qubit-bath coupling strength and spatial separation of the qubits. Moreover, we clarify the relation between single-qubit coherence and two-qubit entanglement and identify parameter regimes in which the terms robust and fragile are no longer appropriate.

arXiv comment7 pages, 3 figures; revised version, accepted for publication in Europhys. Lett

References in corpus (22)

• Entanglement of Formation of an Arbitrary State of Two Qubits
• Quantum state engineering with Josephson-junction devices
• Decoherence Free Subspaces for Quantum Computation
• Dynamical suppression of decoherence in two-state quantum systems
• Noiseless Quantum Codes
• Quantum Computers and Dissipation
• Coherent manipulation of electronic states in a double quantum dot
• Maintaining coherence in Quantum Computers
• Qubit Disentanglement and Decoherence via Dephasing
• Decoherence of quantum registers
• Fault-Tolerant Quantum Computation For Local Non-Markovian Noise
• Phonon decoherence of quantum entanglement: Robust and fragile states
• Robustness of Decoherence-Free Subspaces for Quantum Computation
• Adiabatic Decoherence
• Macroscopic thermal entanglement due to radiation pressure
• Non-Markovian dynamics of double quantum dot charge qubits due to acoustic phonons
• Decoherence of a Measure of Entanglement
• Coherence stabilization of a two-qubit gate by AC fields
• Intrinsic phonon decoherence and quantum gates in coupled lateral quantum dot charge qubits
• Time Scales of Phonon Induced Decoherence of Semiconductor Spin Qubits
• Decoherence in a system of many two--level atoms
• Entanglement production by quantum error correction in the presence of correlated environment

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