Measurable Concurrence of Mixed States

Abstract

We show that bipartite concurrence for rank-2 mixed states of qubits is written by an observable which can be exactly and directly measurable in experiment by local projective measurements, provided that four copies of the composite quantum system are available. In addition, for a tripartite quantum pure state of qubits, the 3-tangle is also shown to be measurable only by projective measurements on the reduced density matrices of a pair of qubits conditioned on four copies of the state.

3 pages

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Cited by in corpus (10)

• Observable estimation of entanglement for arbitrary finite-dimensional mixed states
• Novel Schemes for Directly Measuring Entanglement of General States
• Direct scheme for measuring the geometric quantum discord
• Evolution of entanglement for quantum mixed states
• Universal detection of entanglement in two-qubit states using only two copies
• Viable entanglement detection of unknown mixed states in low dimensions
• Preparing two-atom entangled state in a cavity and probing it via quantum non-demolition measurement
• Probing quantum entanglement, quantum discord, classical correlation, and the quantum state without disturbing them
• Lorentz Invariant Quantum Concurrence for SU(2) x SU(2) spin-parity states
• Measurable genuine tripartite entanglement of ($2\otimes 2\otimes n$)-dimensional quantum states via only two simultaneous copies