Bound entanglement-assisted prepare-and-measure scenarios based on four-dimensional quantum messages
- URL: http://arxiv.org/abs/2502.08293v2
- Date: Wed, 29 Oct 2025 19:19:31 GMT
- Title: Bound entanglement-assisted prepare-and-measure scenarios based on four-dimensional quantum messages
- Authors: István Márton, Erika Bene, Tamás Vértesi,
- Abstract summary: We present a class of linear correlation witnesses that detects bound entanglement within a three-party prepare-and-measure scenario.<n>We relate the detection power of our witnesses for two-ququart Bloch-product-diagonal states to that of the computable cross norm-realignment criterion.
- Score: 0.0
- License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
- Abstract: We present a class of linear correlation witnesses that detects bound entanglement within a three-party prepare-and-measure scenario with four-dimensional quantum messages. We relate the detection power of our witnesses for two-ququart Bloch-product-diagonal states to that of the computable cross norm-realignment (CCNR) criterion. Several bound entangled states in four or even higher dimensions, including those which are useful in metrology, can exceed the separable bound computed by reliable iterative methods. In particular, we show that a prominent two-ququart bound entangled state with a positive partial transpose (PPT) can be mixed with up to $40\%$ isotropic noise and still be detected as entangled by our prepare-and-measure witness. Furthermore, our witnesses appear to be experimentally practical, requiring only the use of qubit rotations on Alice's and Bob's sides and product qubit measurements with binary outcomes on Charlie's side.
Related papers
- Detection of many-body entanglement partitions in a quantum computer [0.05249805590164902]
We present a method to detect entanglement partitions of multipartite quantum systems.<n> Structures like genuinely multipartite entanglement, $m$-separability and entanglement depth are detected as very special cases.
arXiv Detail & Related papers (2025-11-17T19:00:02Z) - Resource-efficient entanglement detection in high-dimensional states via two-qubit witnesses [0.0]
This paper presents an efficient method for detecting entanglement in high-dimensional two-qudit states by mapping the Hilbert space onto the space of two qubits.<n>The proposed approach is not restricted to any specific class of states, successfully identifies a vast majority of pure entangled states.
arXiv Detail & Related papers (2025-09-16T13:19:27Z) - Entanglement Detection Beyond Local Bound with Coarse Calibrated measurements [0.0]
We present a systematic approach for strengthening Bell inequalities for qubit systems.<n>We derive trade-offs between upper bounds for separable states and general states in terms of structure functions.<n>We then strengthen n-partite Bell inequalities for the detection of states exhibiting a diversity of entanglement structures.
arXiv Detail & Related papers (2025-08-05T14:53:38Z) - Quantifying mixed-state entanglement via partial transpose and realignment moments [0.0]
Entanglement plays a crucial role in quantum information science and many-body physics.<n>We introduce families of quantitative entanglement witnesses, constructed from partial realignment and transpose moments.<n>Our witnesses can be efficiently measured using SWAP tests or variants of Bell measurements.
arXiv Detail & Related papers (2025-07-18T11:53:39Z) - Symmetric quantum joint measurements on multiple qubits [0.0]
We describe a method for constructing a symmetric joint measurement basis for three qubits.<n>We demonstrate the expected tetrahedral symmetry of the current measurement basis.<n>This architecture enables us to generalize the two-qubit symmetric joint measurement to an $n$-qubit version.
arXiv Detail & Related papers (2025-03-12T02:01:46Z) - State-witness contraction [0.0]
We present a method to construct entanglement witnesses for arbitrarily large multipartite systems.
As a proof of principle we show that, using little shared quantum resources, the method allows to reuse witnesses unable to detect states with local positive partial transpositions into new ones able to do so.
arXiv Detail & Related papers (2025-02-24T22:44:16Z) - Spectral Representation for Causal Estimation with Hidden Confounders [33.148766692274215]
We address the problem of causal effect estimation where hidden confounders are present.<n>Our approach uses a singular value decomposition of a conditional expectation operator, followed by a saddle-point optimization problem.
arXiv Detail & Related papers (2024-07-15T05:39:56Z) - The signaling dimension in generalized probabilistic theories [48.99818550820575]
The signaling dimension of a given physical system quantifies the minimum dimension of a classical system required to reproduce all input/output correlations of the given system.
We show that it suffices to consider extremal measurements with rayextremal effects, and we bound the number of elements of any such measurement in terms of the linear dimension.
For systems with a finite number of extremal effects, we recast the problem of characterizing the extremal measurements with ray-extremal effects.
arXiv Detail & Related papers (2023-11-22T02:09:16Z) - A U-turn on Double Descent: Rethinking Parameter Counting in Statistical
Learning [68.76846801719095]
We show that double descent appears exactly when and where it occurs, and that its location is not inherently tied to the threshold p=n.
This provides a resolution to tensions between double descent and statistical intuition.
arXiv Detail & Related papers (2023-10-29T12:05:39Z) - Open-Set Likelihood Maximization for Few-Shot Learning [36.97433312193586]
We tackle the Few-Shot Open-Set Recognition (FSOSR) problem, i.e. classifying instances among a set of classes for which we only have a few labeled samples.
We explore the popular transductive setting, which leverages the unlabelled query instances at inference.
Motivated by the observation that existing transductive methods perform poorly in open-set scenarios, we propose a generalization of the maximum likelihood principle.
arXiv Detail & Related papers (2023-01-20T01:56:19Z) - High-dimensional entanglement certification: bounding relative entropy
of entanglement in $2d+1$ experiment-friendly measurements [77.34726150561087]
Entanglement -- the coherent correlations between parties in a quantum system -- is well-understood and quantifiable.
Despite the utility of such systems, methods for quantifying high-dimensional entanglement are more limited and experimentally challenging.
We present a novel certification method whose measurement requirements scale linearly with dimension subsystem.
arXiv Detail & Related papers (2022-10-19T16:52:21Z) - Quadratic pseudospectrum for identifying localized states [68.8204255655161]
quadratic pseudospectrum is a method for approaching systems with incompatible observables.
We derive an important estimate relating the Clifford and quadratic pseudospectra.
We prove that the quadratic pseudospectrum is local, and derive bounds on the errors that are incurred by truncating the system in the vicinity of where the pseudospectrum is being calculated.
arXiv Detail & Related papers (2022-04-22T00:57:09Z) - Search for an efficient entanglement witness operator for bound
entangled states in bipartite quantum systems [0.0]
Entanglement detection problem is one of the important problem in quantum information theory.
There are some powerful entanglement detection criterion such as partial transposition criterion, realignment criterion.
In this work, we take an analytical approach to construct a witness operator.
arXiv Detail & Related papers (2022-04-13T06:41:14Z) - Entanglement swapping and quantum correlations via Elegant Joint
Measurements [5.252277280918264]
We use hyper-entanglement to experimentally realize deterministic entanglement swapping based on quantum Elegant Joint Measurements.
We report measurement fidelities no smaller than $97.4%$.
arXiv Detail & Related papers (2022-03-30T11:09:20Z) - Efficient Bipartite Entanglement Detection Scheme with a Quantum
Adversarial Solver [89.80359585967642]
Proposal reformulates the bipartite entanglement detection as a two-player zero-sum game completed by parameterized quantum circuits.
We experimentally implement our protocol on a linear optical network and exhibit its effectiveness to accomplish the bipartite entanglement detection for 5-qubit quantum pure states and 2-qubit quantum mixed states.
arXiv Detail & Related papers (2022-03-15T09:46:45Z) - Experimentally determining the incompatibility of two qubit measurements [55.41644538483948]
We describe and realize an experimental procedure for assessing the incompatibility of two qubit measurements.
We demonstrate this fact in an optical setup, where the qubit states are encoded into the photons' polarization degrees of freedom.
arXiv Detail & Related papers (2021-12-15T19:01:44Z) - Optimal Entanglement Witness for Cooper Pair Splitters [0.0]
We formulate an entanglement witness that can detect the spin-entanglement using only three cross-correlation measurements of the currents.
Our work paves the way for an experimental detection of the entanglement produced by Cooper pair splitters.
arXiv Detail & Related papers (2021-10-10T12:53:07Z) - Machine-Learning-Derived Entanglement Witnesses [55.76279816849472]
We show a correspondence between linear support vector machines (SVMs) and entanglement witnesses.
We use this correspondence to generate entanglement witnesses for bipartite and tripartite qubit (and qudit) target entangled states.
arXiv Detail & Related papers (2021-07-05T22:28:02Z) - Entanglement Classification via Single Entanglement Measure [0.0]
We show that a single entanglement measure is enough to verify equivalence between generic $n$-qubit states under Local Operations with Classical Communication.
We propose a method to obtain the normal form of a 4-qubit state which bypasses the possibly infinite iterative procedure.
arXiv Detail & Related papers (2021-06-01T23:17:41Z) - Generalized quantum measurements with matrix product states:
Entanglement phase transition and clusterization [58.720142291102135]
We propose a method for studying the time evolution of many-body quantum lattice systems under continuous and site-resolved measurement.
We observe a peculiar phenomenon of measurement-induced particle clusterization that takes place only for frequent moderately strong measurements, but not for strong infrequent measurements.
arXiv Detail & Related papers (2021-04-21T10:36:57Z) - Witnesses of coherence and dimension from multiphoton
indistinguishability tests [0.0]
We experimentally measure a novel type of coherence witness that uses pairwise state comparisons to identify superpositions in a basis-independent way.
Besides coherence witnesses, we show the measurements also serve as a Hilbert-space dimension witness.
arXiv Detail & Related papers (2021-04-19T12:13:51Z) - Generating and detecting bound entanglement in two-qutrits using a
family of indecomposable positive maps [0.0]
We propose an indecomposable positive map for two-qutrit systems.
A corresponding witness operator is constructed and shown to be weakly optimal.
We find a new entangled state which is not detectable by certain other well-known entanglement detection criteria.
arXiv Detail & Related papers (2020-08-29T12:52:27Z) - Distributed, partially collapsed MCMC for Bayesian Nonparametrics [68.5279360794418]
We exploit the fact that completely random measures, which commonly used models like the Dirichlet process and the beta-Bernoulli process can be expressed as, are decomposable into independent sub-measures.
We use this decomposition to partition the latent measure into a finite measure containing only instantiated components, and an infinite measure containing all other components.
The resulting hybrid algorithm can be applied to allow scalable inference without sacrificing convergence guarantees.
arXiv Detail & Related papers (2020-01-15T23:10:13Z)
This list is automatically generated from the titles and abstracts of the papers in this site.
This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.