Physically Realizable Entanglement by Local Continuous Measurements

Abstract

Quantum systems prepared in pure states evolve into mixtures under environmental action. Physically realizable ensembles are the pure state decompositions of those mixtures that can be generated in time through continuous measurements of the environment. Here, we define physically realizable entanglement as the average entanglement over realizable ensembles. We optimize the measurement strategy to maximize and minimize this quantity through local observations on the independent environments that cause two qubits to disentangle in time. We then compare it with the entanglement bounds for the unmonitored system. For some relevant noise sources the maximum realizable entanglement coincides with the upper bound, establishing the scheme as an alternative to locally protect entanglement. However, for local strategies, the lower bound of the unmonitored system is not reached.

version 2; 5 pages, 1 figure; added references;

References in corpus (16)

• Entanglement of Formation of an Arbitrary State of Two Qubits
• Mixed State Entanglement and Quantum Error Correction
• Finite-Time Disentanglement via Spontaneous Emission
• Quantum jumps of light recording the birth and death of a photon in a cavity
• Entanglement of pure states for a single copy
• Vanishing quantum discord is necessary and sufficient for completely positive maps
• Disentanglement and Decoherence by Open System Dynamics
• Direct measurement of finite-time disentanglement induced by a reservoir
• Controlling entanglement by direct quantum feedback
• Optimal control of entanglement via quantum feedback
• Avoiding entanglement sudden-death via measurement feedback control in a quantum network
• Entanglement within the Quantum Trajectory Description of Open Quantum Systems
• Weak measurement and control of entanglement generation
• Inequivalence of pure state ensembles for open quantum systems: the preferred ensembles are those that are physically realizable
• Average Entanglement for Markovian Quantum Trajectories
• Protection of quantum information and optimal singlet conversion through higher dimensional quantum systems and environment monitoring

Cited by in corpus (16)

• Open-System Dynamics of Entanglement
• Recovering Entanglement by Local Operations
• Hidden entanglement, system-environment information flow and non-Markovianity
• Experimental simulation of decoherence in photonics qudits
• Heralded Bell State of Dissipative Qubits Using Classical Light in a Waveguide
• Distant entanglement protected through artificially increased local temperature
• Entanglement-Preserving Limit Cycles from Sequential Quantum Measurements and Feedback
• Dynamics of genuine multipartite correlations in open quantum systems
• Equilibrium and Disorder-induced behavior in Quantum Light-Matter Systems
• Entanglement of a pair of quantum emitters via continuous fluorescence measurements: a tutorial
• Average entanglement dynamics in open two-qubit systems with continuous monitoring
• Quantum filtering one bit at a time
• Markovian dynamics for a quantum/classical system and quantum trajectories
• Diffusive-Gutzwiller approach to the quadratically driven photonic lattice
• Physical consequences of Lindbladian invariance transformations
• Quantifying entanglement in multipartite conditional states of open quantum systems by measurements of their photonic environment