It is well known that the violation of a local uncertainty relation can be used as an indicator for the presence of entanglement. Unfortunately, the practical use of these nonlinear witnesses has been limited to few special cases in the past. However, new methods for computing uncertainty bounds have become available. Here we report on an experimental implementation of uncertainty-based entanglement witnesses, benchmarked in a regime dominated by strong local noise. We combine the new computational method with a local noise tomography in order to design noise-adapted entanglement witnesses. This proof-of-principle experiment shows that quantum noise can be successfully handled by a fully quantum model in order to enhance the ability to detect entanglement.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1103/PhysRevLett.122.220401 | DOI Listing |
J Med Humanit
January 2025
The University of North Carolina School of Medicine, 321 Columbia St, Chapel Hill, NC, 27514, USA.
A growing body of literature explores the intersection of eating disorders and identity formation-an entanglement that makes eating disorders particularly challenging to treat. Narrative medicine is a discipline of the health humanities that is interested in bearing witness to patients' stories with a closeness and rigor that enhances clinical care. The pedagogy of the field is the narrative medicine workshop, which mobilizes close-reading of works of art and reflective writing to improve our understanding of Self and Other.
View Article and Find Full Text PDFPhys Rev Lett
December 2024
Université Paris-Saclay, CNRS, LPTMS, 91405, Orsay, France.
Energy-filtered quantum states are promising candidates for efficiently simulating thermal states. We explore a protocol designed to transition a product state into an eigenstate located in the middle of the spectrum; this is achieved by gradually reducing its energy variance, which allows us to comprehensively understand the crossover phenomenon and the subsequent convergence toward thermal behavior. We introduce and discuss three energy-filtering regimes (short, medium, and long), and we interpret them as stages of thermalization.
View Article and Find Full Text PDFNat Commun
January 2025
Department of Physics and HK Institute of Quantum Science & Technology, The University of Hong Kong, Hong Kong, Hong Kong.
Quantum entanglement uncovers the essential principles of quantum matter, yet determining its structure in realistic many-body systems poses significant challenges. Here, we employ a protocol, dubbed entanglement microscopy, to reveal the multipartite entanglement encoded in the full reduced density matrix of the microscopic subregion in spin and fermionic many-body systems. We exemplify our method by studying the phase diagram near quantum critical points (QCP) in 2 spatial dimensions: the transverse field Ising model and a Gross-Neveu-Yukawa transition of Dirac fermions.
View Article and Find Full Text PDFCommun Math Phys
November 2024
Institute for Quantum Optics and Quantum Information, Austrian Academy of Sciences, Boltzmanngasse 3, 1090 Vienna, Austria.
How can detector click probabilities respond to spatial rotations around a fixed axis, in any possible physical theory? Here, we give a thorough mathematical analysis of this question in terms of "rotation boxes", which are analogous to the well-known notion of non-local boxes. We prove that quantum theory admits the most general rotational correlations for spins 0, 1/2, and 1, but we describe a metrological game where beyond-quantum resources of spin 3/2 outperform all quantum resources of the same spin. We prove a multitude of fundamental results about these correlations, including an exact convex characterization of the spin-1 correlations, a Tsirelson-type inequality for spins 3/2 and higher, and a proof that the general spin- correlations provide an efficient outer SDP approximation to the quantum set.
View Article and Find Full Text PDFPhys Rev Lett
November 2024
Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, England, United Kingdom.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!