Design and experimental performance of local entanglement witness operators

@article{Amaro2020DesignAE,
  title={Design and experimental performance of local entanglement witness operators},
  author={David Amaro and Markus P. M{\"u}ller},
  journal={Physical Review A},
  year={2020}
}
Entanglement is a central concept in quantum information and a key resource for many quantum protocols. In this work we propose and analyze a class of entanglement witnesses that detect the presence of entanglement in subsystems of experimental multi-qubit stabilizer states. The witnesses we propose can be decomposed into sums of Pauli operators and can be efficiently evaluated by either two measurement settings only or at most a number of measurements that only depends on the size of the… 

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References

SHOWING 1-10 OF 148 REFERENCES

Resource-Efficient Measurement-Device-Independent Entanglement Witness.

TLDR
The theory of MDI-EW is extended to remove the necessity of prior knowledge about the two-qubit states to be witnessed and the robustness of this approach against noise is demonstrated by witnessing entanglement down to an entangled state fraction close to 0.4.

Scalable characterization of localizable entanglement in noisy topological quantum codes

TLDR
This paper provides two different prescriptions to characterize noisy stabilizer states, including the surface and the color codes, in terms of localizable entanglement over a subset of qubits, and discusses in detail the methodology of obtaining a local unitary equivalent graph state from a stabilizer state.

Implementation of a measurement-device-independent entanglement witness.

TLDR
This work constructs an attack on the conventional entanglement witness process and demonstrates that a separable state can be falsely identified to be entangled, and designs and experimentally demonstrates a measurement-device-independent entangling witness for a variety of two-qubit states.

Measurement-device-independent entanglement witnesses for all entangled quantum states.

TLDR
This work introduces the concept of measurement-device-independent entanglement witnesses (MDI-EWs), which allow one to demonstrateEntanglement of all entangled quantum states with untrusted measurement apparatuses, and shows how to systematically obtain such MDI-ews from standard entangler witnesses.

Estimating localizable entanglement from witnesses

Computing localizable entanglement for noisy many-particle quantum states is difficult due to the optimization over all possible sets of local projection measurements. Therefore, it is crucial to

Quantitative entanglement witnesses

TLDR
All these tests—based on the very same data—give rise to quantitative estimates in terms of entanglement measures, and if a test is strongly violated, one can also infer that the state was quantitatively very much entangled, in the bipartite and multipartite setting.

Entanglement detection in the stabilizer formalism

We investigate how stabilizer theory can be used for constructing sufficient conditions for entanglement. First, we show how entanglement witnesses can be derived for a given state, provided some

Three qubits can be entangled in two inequivalent ways

Invertible local transformations of a multipartite system are used to define equivalence classes in the set of entangled states. This classification concerns the entanglement properties of a single

Optimization of entanglement witnesses

An entanglement witness (EW) is an operator that allows to detect entangled states. We give necessary and sufficient conditions for such operators to be optimal, i.e. to detect entangled states in an

Experimental Measurement-Device-Independent Entanglement Detection

TLDR
This experimental demonstration of measurement-device-independent (MDI) entanglement detection using witness method for general two qubits photon polarization systems can be generalized for the investigation of properties of quantum systems and for the realization of cryptography and communication protocols.
...