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Schmidt decomposition is a powerful tool in quantum information. While Schmidt decomposition is universal for bipartite states, its not for multipartite states. In this article, we review properties of bipartite Schmidt decompositions and…

Quantum Physics · Physics 2025-02-15 Mithilesh Kumar

In this study, we enhance the understanding of entanglement transformations and their quantification by extending the concept of Schmidt vector from pure to mixed bipartite states, exploiting the lattice structure of majorization. The…

Quantum Physics · Physics 2024-07-25 F. Meroi , M. Losada , G. M. Bosyk

The full Schmidt decomposition of spatiotemporally entangled states generated from spontaneous parametric down-conversion (SPDC) has not been carried out until now due to the immense computational complexity arising from the large…

Quantum Physics · Physics 2026-02-10 Rakesh Pradhan , Girish Kulkarni

In this work, we present a theoretical and experimental study about the spatial correlations of paired photons generated by type-II spontaneous parametric down-conversion. In particular, we show how these correlations can be positive or…

We derive an exact formula for the angular Schmidt spectrum of the orbital angular momentum (OAM)-entangled states produced by parametric down-conversion (PDC). We show that our formula yields true theoretical spectrum without any…

Optics · Physics 2018-07-05 Girish Kulkarni , Lavanya Taneja , Shaurya Aarav , Anand K. Jha

Entangled two-mode Gaussian states constitute an important building block for continuous variable quantum computing and communication protocols. In this work, we theoretically study two-mode bipartite states which are extracted from…

Quantum Physics · Physics 2026-01-21 Denis A. Kopylov , Torsten Meier , Polina R. Sharapova

Classical entanglement refers to non-separable correlations between the polarization direction and the polarization amplitude of a light field. The degree of entanglement is quantified by the Schmidt number, taking the value of unity for a…

Quantum Physics · Physics 2023-07-19 Ziyang You , Zikang Tang , Hou Ian

Lossless filtering of a single coherent (Schmidt) mode from spatially multimode radiation is a problem crucial for optics in general and for quantum optics in particular. It becomes especially important in the case of nonclassical light…

Genuine high-dimensional entanglement, i.e. the property of having a high Schmidt number, constitutes a resource in quantum communication, overcoming limitations of low-dimensional systems. States with a positive partial transpose (PPT), on…

Quantum Physics · Physics 2018-11-21 Marcus Huber , Ludovico Lami , Cécilia Lancien , Alexander Müller-Hermes

We study exact local compression of a quantum bipartite state; that is, applying local quantum operations to reduce the dimensions of the Hilbert spaces while perfectly preserving the correlation. We provide a closed-form expression for the…

Quantum Physics · Physics 2025-05-08 Kohtaro Kato

In quantum information theory, the Schmidt rank is a fundamental measure for the entanglement dimension of a pure bipartite state. Its natural definition uses the Schmidt decomposition of vectors on bipartite Hilbert spaces, which does not…

Quantum Physics · Physics 2024-06-21 Lauritz van Luijk , René Schwonnek , Alexander Stottmeister , Reinhard F. Werner

Higher-dimensional entanglement is a valuable resource for several quantum information processing tasks, and is often characterized by the Schmidt number and specific classes of entangled states beyond qubit-qubit and qubit-qutrit systems.…

Quantum Physics · Physics 2025-07-28 Bivas Mallick , Ananda G. Maity , Nirman Ganguly , A. S. Majumdar

The measurement of joint signal-idler photon-number distribution of a field obtained from spontaneous parametric downconversion using an intensified CCD camera is presented. It is shown that a classicality criterion is violated directly by…

Quantum Physics · Physics 2015-05-13 Ondrej Haderka , Jan Perina , Martin Hamar

Enhancing the precision of a measurement requires maximizing the information that can be gained about the quantity of interest from probing a system. For optical based measurements, such an enhancement can be achieved through two…

The probability of large deviations of the smallest Schmidt eigenvalue for random pure states of bipartite systems, denoted as $A$ and $B$, is computed analytically using a Coulomb gas method. It is shown that this probability, for large…

Quantum Physics · Physics 2021-08-12 Udaysinh T. Bhosale

Entanglement is a unique feature of quantum mechanics. In coupled systems of light and matter, entanglement manifests itself in the linear superposition of multipartite quantum states (e.g., parametrized by the multiple spatial, spectral,…

Quantum Physics · Physics 2024-11-14 Charles Roques-Carmes , Aviv Karnieli , David A. B. Miller , Shanhui Fan

Optical parametric down-conversion is a common source for the generation of non-classical correlated photonic states. Using a parametric down-conversion source and photon-number resolving detectors, we measure the two-mode photon-number…

Quantum Physics · Physics 2014-02-04 L. Dovrat , M. Bakstein , D. Istrati , E. Megidish , A. Halevy , H. S. Eisenberg

The well-known Schmidt decomposition, or equivalently, the complex singular value decomposition, states that a pure quantum state of a bipartite system can always be brought into a "diagonal" form using local unitary transformations. In…

Quantum Physics · Physics 2024-01-17 Emanuel Malvetti

A definition of the Schmidt number of a state of an infinite dimensional bipartite quantum system is given and properties of the corresponding family of Schmidt classes are considered. The existence of states with a given Schmidt number…

Quantum Physics · Physics 2013-04-26 M. E. Shirokov

We present a generalized Schmidt decomposition for a pure system with any number of two-level subsystems. The basis is symmetric under the permutation of the parties and is derived from the product state defining the injective tensor norm…

Quantum Physics · Physics 2009-01-06 Levon Tamaryan , DaeKil Park , Sayatnova Tamaryan