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The dimensionality of entanglement is a core tenet of quantum information processing, especially quantum communication and computation. While it is natural to think of this dimensionality in finite dimensional systems, many of the…

Quantum Physics · Physics 2025-09-04 Shuheng Liu , Jiajie Guo , Matteo Fadel , Qiongyi He , Marcus Huber , Giuseppe Vitagliano

A strategy to evaluate the distribution of the largest Schmidt eigenvalue for entangled random pure states of bipartite systems is proposed. We point out that the multiple integral defining the sought quantity for a bipartition of sizes N,…

Statistical Mechanics · Physics 2011-01-21 Pierpaolo Vivo

We report the realization of a bright ultrafast two-mode squeezer based on type II parametric downconversion (PDC) in periodically poled $\mathrm{KTiOPO_4}$ (PP-KTP) waveguides. It produces a pulsed two-mode squeezed vacuum state: a…

Quantum Physics · Physics 2011-01-10 Andreas Eckstein , Andreas Christ , Peter J. Mosley , Christine Silberhorn

We consider bi-linear analogues of $s$-positivity for linear maps. The dual objects of these notions can be described in terms of Schimdt ranks for tri-tensor products and Schmidt numbers for tri-partite quantum states. These tri-partite…

Quantum Physics · Physics 2016-03-22 Kyung Hoon Han , Seung-Hyeok Kye

We study theoretically the squeezing spectrum and second-order correlation function of the output light for an optomechanical system in which a mechanical oscillator modulates the cavity linewidth (dissipative coupling). We find strong…

Mesoscale and Nanoscale Physics · Physics 2015-12-14 Dainius Kilda , Andreas Nunnenkamp

We provide a toolbox for continuous variables quantum state engineering and characterization of biphoton states produced by spontaneous parametric down conversion in a transverse pump configuration. We show that the control of the pump…

We investigate the equation of state w(z) in a non-parametric form using the latest compilations of distance luminosity from SNe Ia at high z. We combine the inverse problem approach with a Monte Carlo to scan the space of priors. On the…

Astrophysics · Physics 2010-04-23 Cristina Espana-Bonet , Pilar Ruiz-Lapuente

Orbital Angular Momentum (OAM) modes are an important resource used in various branches of quantum science and technology due to their unique helical structure and countably infinite basis. Generating light that simultaneously carries…

Quantum Physics · Physics 2025-01-29 D. Scharwald , L. Gehse , P. R. Sharapova

We introduce semidefinite programming hierarchies for benchmarking relevant entanglement properties in the high-dimensional steering scenario. Firstly, we provide a general method for detecting the entanglement dimensionality through…

Quantum Physics · Physics 2025-03-11 Nicola D'Alessandro , Carles Roch i Carceller , Armin Tavakoli

We explore the use of higher-order Hermite-Gauss modes for sensing optically induced transverse displacements. In the small-displacement regime, we show that projective measurements onto the two neighboring spatial modes yield optimal…

Optics · Physics 2025-06-04 Dilip Paneru , Alessio D'Errico , Ebrahim Karimi

Using parametric conversion induced by a Shapiro-type resonance, we produce and characterize a two-mode squeezed vacuum state in a sodium spin 1 Bose-Einstein condensate. Spin-changing collisions generate correlated pairs of atoms in the…

Quantum Gases · Physics 2020-07-27 An Qu , Bertrand Evrard , Jean Dalibard , Fabrice Gerbier

We refute the widely held belief that the quantum weak value necessarily pertains to weak measurements. To accomplish this, we use the transverse position of a beam as the detector for the conditioned von Neumann measurement of a system…

Quantum Physics · Physics 2013-01-16 J. Dressel , A. N. Jordan

A light beam is said to be position squeezed if its position can be determined to an accuracy beyond the standard quantum limit. We identify the position and momentum observables for bright optical beams and show that position and momentum…

Quantum Physics · Physics 2009-11-11 Magnus T. L. Hsu , Warwick P. Bowen , Nicolas Treps , Ping Koy Lam

Production and verification of multipartite quantum state are an essential step in quantum information processing. In this work, we propose an efficient method to decompose symmetric multipartite observables, which are invariant under…

Quantum Physics · Physics 2019-05-21 You Zhou , Chenghao Guo , Xiongfeng Ma

The degree of polarization of a quantum state can be defined as its Hilbert-Schmidt distance to the set of unpolarized states. We demonstrate that the states optimizing this degree for a fixed average number of photons $\bar{N}$ present a…

Quantum Physics · Physics 2008-07-25 L. L. Sanchez-Soto , E. C. Yustas , G. Bjork , A. B. Klimov

We analyze features of mixed biphoton polarization states which arise from pure states of polarization-frequency biphoton ququarts after averaging over frequencies of photons. For mixed states we find their concurrence C, Schmidt parameter…

Quantum Physics · Physics 2011-05-13 M. V. Fedorov , P. A. Volkov , J. M. Mikhailova

We investigate the dimensionality of bipartite quantum systems by construction of a device-independent null witness test. This test assesses whether a given bipartite state conforms with the expected quantum dimension, Schmidt number, and…

Quantum Physics · Physics 2024-10-10 Josep Batle , Tomasz Białecki , Tomasz Rybotycki , Jakub Tworzydło , Adam Bednorz

Entanglement of bipartite squeezed states generated by holomorphic Hermite functions of two complex variables is investigated using phase-space approach based on the Wigner distribution function. Orthogonality of the holomorphic Hermite…

Quantum Physics · Physics 2025-08-15 K. Górska , A. Horzela , D. Kołaczek , B. J. Spisak , F. H. Szafraniec

We address local quantum estimation of bilinear Hamiltonians probed by Gaussian states. We evaluate the relevant quantum Fisher information (QFI) and derive the ultimate bound on precision. Upon maximizing the QFI we found that single- and…

Quantum Physics · Physics 2009-11-13 Roberto Gaiba , Matteo G A Paris

We investigate the effects of weak value amplification on the nonclassical properties of two-mode squeezing vacuum state. To show the advantages of the two-mode squeezing vacuum state based post-selective weak measurements.

Quantum Physics · Physics 2025-02-18 Janarbek Yuanbek , Yi-Fang Ren , Ahmad Abliz , Yusuf Turek