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Related papers: Quasistates and quasiprobabilities

200 papers

We provide theory, algorithms, and simulations of non-equilibrium quantum systems using a one-dimensional (1D) completely-positive (CP), matrix-product (MP) density-operator ($\rho$) representation. By generalizing the matrix product…

Quantum Physics · Physics 2025-09-16 Amit Jamadagni , Eugene Dumitrescu

Classical probability distributions on sets of sequences can be modeled using quantum states. Here, we do so with a quantum state that is pure and entangled. Because it is entangled, the reduced densities that describe subsystems also carry…

Quantum Physics · Physics 2020-12-10 Tai-Danae Bradley , E. Miles Stoudenmire , John Terilla

The act of describing how a physical process changes a system is the basis for understanding observed phenomena. For quantum-mechanical processes in particular, the affect of processes on quantum states profoundly advances our knowledge of…

Quantum Physics · Physics 2017-10-20 Jen-Hsiang Hsieh , Shih-Hsuan Chen , Che-Ming Li

Classical simulation of quantum physics is a central approach to investigating physical phenomena. Quantum computers enhance computational capabilities beyond those of classical resources, but it remains unclear to what extent existing…

Quantum Physics · Physics 2025-01-28 Adrián Pérez-Salinas , Patrick Emonts , Jordi Tura , Vedran Dunjko

Suppose you receive a sequence of qubits where each qubit is guaranteed to be in one of two pure states, but you do not know what those states are. Your task is to determine the states. This can be viewed as a kind of quantum state learning…

The new scheme employed (throughout the thermodynamic phase space), in the statistical thermodynamic investigation of classical systems, is extended to quantum systems. Quantum Nearest Neighbor Probability Density Functions are formulated…

Statistical Mechanics · Physics 2015-06-25 U. F. Edgal , D. L. Huber

Motivated by real-world situations found in high energy particle physics, we consider a generalisation of the likelihood-ratio estimation task to a quasiprobabilistic setting where probability densities can be negative. By extension, this…

Machine Learning · Statistics 2024-10-15 Matthew Drnevich , Stephen Jiggins , Judith Katzy , Kyle Cranmer

How to give a statistical description of thermodynamics in quantum systems is an open fundamental question. Concerning the work, the presence of initial quantum coherence in the energy basis can give rise to a quasiprobability of work,…

Quantum Physics · Physics 2022-11-15 Gianluca Francica

Quantification of nonclassicality and entanglement in a quantum state is crucial for quantum advantage in information processing and computation. Robustness is one of the tractable measures for quantifying quantum resources. Gaussian states…

Quantum Physics · Physics 2023-09-22 Xiao-yu Chen

This paper aims to stress the role of the Cahill-Glauber quasi-probability densities in defining, detecting, and quantifying the non-classicality of field states in quantum optics. The distance between a given pure state and the set of all…

Quantum Physics · Physics 2020-04-22 Paulina Marian , Tudor A. Marian

We review here the quantum mechanics of some noncommutative theories in which no state saturates simultaneously all the non trivial Heisenberg uncertainty relations. We show how the difference of structure between the Poisson brackets and…

High Energy Physics - Theory · Physics 2009-11-10 Musongela Lubo

We characterize entanglement subject to its definition over real and complex, composite quantum systems. In particular, a method is established to assess quantum correlations with respect to a selected number system, illuminating the deeply…

The machinery of qubit-portraits of qudit states, recently presented, is consider here in more details in order to characterize the presence of quantum correlations in bipartite qudit states. In the tomographic representation of quantum…

Quantum Physics · Physics 2008-11-26 C. Lupo , V. I. Man'ko , G. Marmo

The Schmidt decomposition is the go-to tool for measuring bipartite entanglement of pure quantum states. Similarly, it is possible to study the entangling features of a quantum operation using its operator-Schmidt, or tensor product…

Quantum Physics · Physics 2024-07-12 Refik Mansuroglu , Arsalan Adil , Michael J. Hartmann , Zoë Holmes , Andrew T. Sornborger

The questions we raise in this letter are as follows: What is the most general representation of a quantum state at a single point in time? Can we adapt the current formalisms to situations where the order of quantum operations is…

Quantum Physics · Physics 2024-06-21 Onur Pusuluk , Zafer Gedik , Vlatko Vedral

Any quasi-probability representation of a no-signaling system -- including quantum systems -- can be simulated via a purely classical scheme by allowing signed events and a cancellation procedure. This raises a fundamental question: What…

Quantum Physics · Physics 2025-08-11 Adam Brandenburger , Pierfrancesco La Mura

An alternative methodology to investigate indirect polyatomic processes with quasi-classical trajectories is proposed, which effectively avoids any binning or weighting procedure while provides rovibrational resolution. Initial classical…

We investigate features of the quasi-joint-probability distribution for finite-state quantum systems, especially the two-state and three-state quantum systems, comparing different types of quasi-joint-probability distributions based on the…

Quantum Physics · Physics 2024-04-01 Shun Umekawa , Jaeha Lee , Naomichi Hatano

Simulating quantum nonlocality and steering requires augmenting pre-shared randomness with non-vanishing communication cost. This prompts the question of how one may provide such an operational characterization for the quantumness of…

Quantum Physics · Physics 2017-03-22 C. Jebaratnam , S. Aravinda , R. Srikanth

We have developed a formalism that includes both quasibound states with real energies and quantum resonances within the same theoretical framework, and that admits a clean and unambiguous distinction between these states and the states of…

Quantum Physics · Physics 2014-03-11 Curt A. Moyer