Proving genuine multiparticle entanglement from separable nearest-neighbor marginals

Paraschiv, Marius; Miklin, Nikolai; Moroder, Tobias; Gühne, Otfried

doi:10.1103/physreva.98.062102

Cited by 12 publications

(32 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Another interesting open question concerns the possibility to detect experimentally GME by measuring not all but only some separable marginals as it was proposed theoretically in Ref. [34]. A large and completely unexplored area of research eventually comprise questions related to the existence and experimental observability of the investigated phenomenon in the realm of Gaussian states.…”

Section: Discussionmentioning

confidence: 99%

Verifying genuine multipartite entanglement of the whole from its separable parts

Mičuda

Stárek

Provazník

et al. 2019

Optica

View full text Add to dashboard Cite

We prove experimentally the predicted existence of a three-qubit quantum state with genuine multipartite entanglement which can be certified solely from its separable two-qubit reduced density matrices. The qubits are encoded into different degrees of freedom of a pair of correlated photons and the state is prepared by letting the photons to propagate through a linear optical circuit. The presence of genuine multipartite entanglement is verified by finding numerically a fully decomposable entanglement witness acting nontrivially only on the reductions of the global state. Our result confirms viability of detection of emerging global properties of composite quantum systems from their parts which lack the properties.

show abstract

Section: Discussionmentioning

confidence: 99%

Verifying genuine multipartite entanglement of the whole from its separable parts

Mičuda

Stárek

Provazník

et al. 2019

Optica

View full text Add to dashboard Cite

show abstract

“…This example shows that the set of locally compatible separable states can be a very bad outer approximation to the set of ensembles admitting a separable extension. Moreover, as proven in [12,27,28], this is so even when one demands in addition the existence of an overall quantum state for the state ensemble. The need of constructions like our hierarchies to address the entanglement marginal problem is thus vindicated.…”

Section: Particles In a Star Configurationmentioning

confidence: 99%

Entanglement marginal problems

Navascués

Baccari

Acín

2021

Quantum

View full text Add to dashboard Cite

We consider the entanglement marginal problem, which consists of deciding whether a number of reduced density matrices are compatible with an overall separable quantum state. To tackle this problem, we propose hierarchies of semidefinite programming relaxations of the set of quantum state marginals admitting a fully separable extension. We connect the completeness of each hierarchy to the resolution of an analog classical marginal problem and thus identify relevant experimental situations where the hierarchies are complete. For finitely many parties on a star configuration or a chain, we find that we can achieve an arbitrarily good approximation to the set of nearest-neighbour marginals of separable states with a time (space) complexity polynomial (linear) on the system size. Our results even extend to infinite systems, such as translation-invariant systems in 1D, as well as higher spatial dimensions with extra symmetries.

show abstract

“…The states with that remarkable property share similarity with entangled states [1] as both exhibit a counterintuitive relationship between the whole and its parts. It is not surprising then, that examples of states with a global property which can be inferred from parts lacking the property were nonlocal correlations [2,3] and in particular multipartite entanglement [4][5][6][7][8][9]. Out of the many flavours of multipartite entanglement [10], the main attention naturally fell on its strongest form, the genuine multipartite entanglement, which is behind the multipartite tests of quantum nonlocality [11], complex behaviour of strongly correlated systems [12], certain models of quantum computing [13] and increased precision of quantum measurements [14].…”

Section: Introductionmentioning

confidence: 99%

“…Interestingly, genuine multipartite entanglement can be detected even from a smaller set of separable marginals. Indeed, multiqubit states can be found possessing all two-qubit marginals separable, whose genuine multipartite entanglement can be inferred only from the so called minimal set of two-qubit marginals [9]. The minimal set covers any part of the entire system and it contains only marginals between nearest-neighbours, which guarantees that knowledge of the set suffices to confirm global entanglement.…”

Section: Introductionmentioning

confidence: 99%

Convicting emergent multipartite entanglement with evidence from a partially blind witness

Nordgren¹,

Leskovjanová²,

Provazník³

et al. 2021

Preprint

View full text Add to dashboard Cite

Genuine multipartite entanglement underlies correlation experiments corroborating quantum mechanics and it is an expedient empowering many quantum technologies. One of many counterintuitive facets of genuine multipartite entanglement is its ability to exhibit an emergent character, that is, one can infer its presence in some multipartite states merely from a set of its separable marginals. Here, we show that the effect can be found also in the context of Gaussian states of bosonic systems. Specifically, we construct examples of multimode Gaussian states carrying genuine multipartite entanglement which can be verified solely from separable nearest-neighbour two-mode marginals. The key tool of our construction is a genuine multipartite entanglement witness acting only on some two-mode reductions of the global covariance matrix, which we find by a numerical solution of a semi-definite programme. We also propose an experimental scheme for preparation of the simplest three-mode state, which requires interference of three correlatively displaced squeezed beams on two beam splitters. Besides revealing the concept of emergent genuine multipartite entanglement in the Gaussian scenario and bringing it closer to experimentally testable form, our results pave the way to effective diagnostics methods of global properties of multipartite states without complete tomography.

show abstract

Proving genuine multiparticle entanglement from separable nearest-neighbor marginals

Cited by 12 publications

References 29 publications

Verifying genuine multipartite entanglement of the whole from its separable parts

Verifying genuine multipartite entanglement of the whole from its separable parts

Entanglement marginal problems

Convicting emergent multipartite entanglement with evidence from a partially blind witness

Contact Info

Product

Resources

About