Entanglement certification from theory to experiment

@article{Friis2018EntanglementCF,
  title={Entanglement certification from theory to experiment},
  author={Nicolai Friis and Giuseppe Vitagliano and Mehul Malik and Marcus Huber},
  journal={Nature Reviews Physics},
  year={2018},
  volume={1},
  pages={72-87}
}
Entanglement is an important resource for quantum technologies. There are many ways quantum systems can be entangled, ranging from the two-qubit case to entanglement in high dimensions or between many parties. Consequently, many entanglement quantifiers and classifiers exist, corresponding to different operational paradigms and mathematical techniques. However, for most quantum systems, exactly quantifying the amount of entanglement is extremely demanding, if at all possible. Furthermore, it is… 

A perspective on few-copy entanglement detection in experiments

TLDR
An overview is provided of a probabilistic approach that enables high-confidence genuine multipartite entanglement detection using an exceptionally low number of state copies, and a study is presented that shows that this protocol remains efficient also in the presence of noise, thus confirming the practicality of the method for near-term quantum devices and its suitability for complex experimental settings.

The Schmidt number of a quantum state cannot always be device-independently certified

TLDR
A simple proof that there exist quantum states, whose entanglement content, as measured by the Schmidt number, cannot be device-independently certified for all possible sequential measurements on any number of copies.

From entanglement certification with quench dynamics to multipartite entanglement of interacting fermions

Multipartite entanglement, such as witnessed through the quantum Fisher information (QFI), is a crucial resource for quantum technologies, but its experimental certification is highly challenging.

Few‐Copy Entanglement Detection in the Presence of Noise

TLDR
An overview is provided of a probabilistic approach that enables high‐confidence genuine multipartite entanglement detection using an exceptionally low number of state copies, and a study is presented that shows that this protocol remains efficient also in the presence of noise, thus confirming the practicality of the method for near‐term quantum devices and its suitability for complex experimental settings.

Optimal Entanglement Certification from Moments of the Partial Transpose.

TLDR
This work proposes two general entanglement detection methods based on the moments of the partially transposed density matrix and provides a family ofEntanglement criteria, of which the lowest order reduces to the known p_{3}-positive-partial-transpose criterion proposed in A. Elben et al.

Entanglement Quantification in Atomic Ensembles.

TLDR
This work analytically derives the lower bounds of broad families of entanglement criteria based on variances of arbitrary operators and lower bounding the best separable approximation and the generalized robustness only from measurements of first and second moments of the collective spin operator.

Detecting and quantifying entanglement on near-term quantum devices

Quantum entanglement is a key resource in quantum technology, and its quantification is a vital task in the current noisy intermediate-scale quantum (NISQ) era. This paper combines hybrid

Detection of quantum correlations

One of the main foci of modern applied quantum information theory is the production of large-scale quantum entanglement involving many particles, to achieve the next-generation quantum technologies.

Unified approach to witness non-entanglement-breaking quantum channels

The ability of quantum devices to preserve or distribute entanglement is essential in employing quantum technologies. Such ability is described and guaranteed by the nonentanglement-breaking (nonEB)

Detecting multipartite entanglement structure with minimal resources

TLDR
This work proposes a systematic method using very few local measurements to detect multipartite entanglement structures based on the graph state and develops a family of efficient witness operators to detect theEntanglement between subsystems under any partitions and hence the entanglements intactness.
...

References

SHOWING 1-10 OF 355 REFERENCES

Quantum entanglement

All our former experience with application of quantum theory seems to say that what is predicted by quantum formalism must occur in the laboratory. But the essence of quantum formalism— entanglement,

Measurements in two bases are sufficient for certifying high-dimensional entanglement

TLDR
It is shown how carefully constructed measurements in two bases can be used to faithfully and efficiently certify bipartite high-dimensional states and their entanglement for any physical platform by measuring quantum states twice in two different bases.

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.

Free-Space distribution of entanglement and single photons over 144 km

Quantum Entanglement is the essence of quantum physics and inspires fundamental questions about the principles of nature. Moreover it is also the basis for emerging technologies of quantum

Measuring entanglement entropy in a quantum many-body system

TLDR
Making use of the single-site-resolved control of ultracold bosonic atoms in optical lattices, two identical copies of a many-body state are prepared and interfered to directly measure quantum purity, Rényi entanglement entropy, and mutual information.

Experimental long-lived entanglement of two macroscopic objects

TLDR
The robust and long-lived entanglement of material objects demonstrated here to be useful in quantum information processing, including teleportation of quantum states of matter and quantum memory is expected.

Measuring multipartite entanglement via dynamic susceptibilities

Entanglement plays a central role in our understanding of quantum many body physics, and is fundamental in characterising quantum phases and quantum phase transitions. Developing protocols to detect

Entanglement between two spatially separated atomic modes

TLDR
The generation of entanglement between two spatially separated clouds is presented by splitting an ensemble of ultracold identical particles prepared in a twin Fock state: because the clouds can be addressed individually, the experiments open a path to exploit the available entangled states of indistinguishable particles for quantum information applications.

Quantifying high-dimensional entanglement with Einstein-Podolsky-Rosen correlations

TLDR
It is shown that the violation of recent entropic witnesses of the Einstein-Podolsky-Rosen paradox also provides tight lower bounds to multiple entanglement measures, such as the $\textit{entanglement of formation}$ and the $\ textit{distillableEntanglement}$, among others.

Entanglement distribution beyond qubits or: How I stopped worrying and learned to love the noise

TLDR
This study is able to certify entanglement in the photonic orbital-angular-momentum and energy-time degrees of freedom up to noise conditions corresponding to a noise fraction of 63% and 92% respectively, thus paving the way towards practical quantum communication systems that are able to surpass the current noise and distance limitations of state-of-the-art quantum technologies.
...