Optimal estimation of entanglement and discord in two-qubit states
arXiv:1810.09331 · doi:10.1038/s41598-019-39334-8
Abstract
Recently, the fast development of quantum technologies led to the need for tools allowing the characterization of quantum resources. In particular, the ability to estimate non-classical aspects, e.g. entanglement and quantum discord, in two-qubit systems, is relevant to optimise the performance of quantum information processes. Here we present an experiment in which the amount of entanglement and discord are measured exploiting different estimators. Among them, some will prove to be optimal, i.e., able to reach the ultimate precision bound allowed by quantum mechanics. These estimation techniques have been tested with a specific family of states ranging from nearly pure Bell states to completely mixed states. This work represents a significant step in the development of reliable metrological tools for quantum technologies.
References in corpus (36)
- Quantum entanglement
- A computable measure of entanglement
- Separability of Mixed States: Necessary and Sufficient Conditions
- Introducing Quantum Discord
- Entanglement detection
- Quantifying Entanglement
- Quantum discord and the power of one qubit
- Necessary and sufficient condition for non-zero quantum discord
- Bell Inequalities and the Separability Criterion
- Generalized uncertainty relations: Theory, examples, and Lorentz invariance
- Witnessing multipartite entanglement
- Gaussian quantum discord
- Research on Hidden Variable Theories: a review of recent progresses
- Quantum discord as resource for remote state preparation
- Quantum discord for general two--qubit states: Analytical progress
- Detection of entanglement with few local measurements
- Quantitative entanglement witnesses
- A comparison of the entanglement measures negativity and concurrence
- Experimental Detection of Entanglement with Polarized Photons
- When are correlations quantum? -- Verification and quantification of entanglement by simple measurements
- Anisotropically high entanglement of biphotons generated in spontaneous parametric down conversion
- Statistical Geometry in Quantum Mechanics
- Multipartite entanglement detection via structure factors
- Statistical Estimation of Quantum Tomography Protocols Quality
- Experimental estimation of entanglement at the quantum limit
- Optimal estimation of entanglement
- Characterization of Spectral Entanglement of Spontaneous Parametric-Down Conversion Biphotons
- Statistical estimation of the quality of quantum-tomography protocols
- Two-Photon Polarization Interference for Pulsed SPDC in a PPKTP Waveguide
- Witnessed Entanglement
- Experimental estimation of quantum discord for polarization qubit and the use of fidelity to assess quantum correlations
- Optimal estimation of entanglement in optical qubit systems
- Quantitative verification of entanglement and fidelities from incomplete measurement data
- Robustness of raw quantum tomography
- Characterizing and measuring multipartite Entanglement
- Characterizing Entanglement Sources
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- Tutorial: Optical quantum metrology
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- Correlation Minor Norms, Entanglement Detection and Discord
- Stationary two-qubit entanglement mediated by one-dimensional plasmonic nanoarrays
- Isospectral oscillators as a resource for quantum information processing