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We prove exponential concentration estimates and a strong law of large numbers for a particle system that is the simplest representative of a general class of models for 2D grain boundary coarsening. The system consists of $n$ particles in…

Probability · Mathematics 2017-04-28 Joe Klobusicky , Govind Menon

Non-classical states of light find applications in enhancing the performance of optical interferometric experiments, with notable example of gravitational wave-detectors. Still, the presence of decoherence hinders significantly the…

Quantum Physics · Physics 2018-08-17 R. Demkowicz-Dobrzanski , M. Jarzyna , J. Kolodynski

Recently, the dynamics of quantum systems that involve both unitary evolution and quantum measurements have attracted attention due to the exotic phenomenon of measurement-induced phase transitions. The latter refers to a sudden change in a…

Quantum Physics · Physics 2025-06-23 Ryotaro Suzuki , Jonas Haferkamp , Jens Eisert , Philippe Faist

We investigate tight monogamy relations of multiparty quantum entanglement for any quantum state in this paper. First, we obtain a class of lower bounds for multiparty quantum systems which improve the previous results. Next, we establish a…

Quantum Physics · Physics 2022-11-23 Hui Li , Ting Gao , Fengli Yan

The striking differences between quantum and classical systems predicate disruptive quantum technologies. We peruse quantumness from a variety of viewpoints, concentrating on phase-space formulations because they can be applied beyond…

Quantum Physics · Physics 2020-12-07 Aaron Z. Goldberg , Andrei B. Klimov , Markus Grassl , Gerd Leuchs , Luis L. Sánchez-Soto

We study a phenomenon occuring in various areas of quantum physics, in which an observable density (such as an energy density) which is classically pointwise nonnegative may assume arbitrarily negative expectation values after quantisation,…

Mathematical Physics · Physics 2007-05-23 Simon P. Eveson , Christopher J. Fewster , Rainer Verch

We investigate permutation-invariant continuous variable quantum states and their covariance matrices. We provide a complete characterization of the latter with respect to permutation-invariance, exchangeability and representing convex…

Quantum Physics · Physics 2009-11-13 Robert Koenig , Michael M. Wolf

Considering pure quantum states, entanglement concentration is the procedure where from $N$ copies of a partially entangled state, a single state with higher entanglement can be obtained. Getting a maximally entangled state is possible for…

Quantum Physics · Physics 2023-04-12 L. Palma Torres , M. A. Solís-Prosser , O. Jiménez , E. S. Gómez , A. Delgado

We prove the approach to equilibrium of quenched isolated quantum systems for which the change in the Hamiltonian brought about by the quench satisfies a certain closed commutator algebra with all the extensive integrals of motion of the…

Statistical Mechanics · Physics 2016-12-01 E. Solano-Carrillo

In a seminal paper [8] it was shown that Heisenberg-limited measurements could be achieved without using entangled states by coupling the quantum resources to a common environment that could be measured, at least, in part. The authors also…

Quantum Physics · Physics 2025-09-25 D. Ballester , Yu. V. Arkhipov , I. M. Tkachenko

The problem of quantum state estimation is crucial in the development of quantum technologies. In particular, the use of symmetric quantum states is useful in many relevant applications. In this work, we analyze the task of reconstructing…

Quantum Physics · Physics 2024-08-20 Federico Holik , Marcelo Losada , Giannina Zerr , Lorena Rebón , Diego Tielas

We present a reliable algorithm to evaluate quantum discord for general two--qubit states, amending and extending an approach recently put forward for the subclass of X--states. A closed expression for the discord of arbitrary states of two…

Quantum Physics · Physics 2011-05-23 Davide Girolami , Gerardo Adesso

It is known that the overlap of two energy eigenstates in a decaying quantum system is bounded from above by a function of the energy detuning and the individual decay rates. This is usually traced back to the positive definiteness of an…

Quantum Physics · Physics 2019-12-23 Jan Wiersig

Quantum optics bridges esoteric notions of entanglement and superposition with practical applications like metrology and communication. Throughout, there is an interplay between information theoretic concepts such as entropy and physical…

Quantum Physics · Physics 2025-01-07 Anaelle Hertz , Noah Lupu-Gladstein , Khabat Heshami , Aaron Z. Goldberg

There are fundamental limits to the accuracy with which one can determine the state of a quantum system. I give an overview of the main approaches to quantum state discrimination. Several strategies exist. In quantum hypothesis testing, a…

Quantum Physics · Physics 2009-11-06 Anthony Chefles

Measurement-based quantum computing enables universal quantum computing with only adaptive single-qubit measurements on certain many-qubit states, such as the graph state, the Affleck-Kennedy-Lieb-Tasaki (AKLT) state, and several…

Quantum Physics · Physics 2017-11-15 Tomoyuki Morimae

Nonorthogonal quantum state discrimination (QSD) plays an important role in quantum information and quantum communication. In addition, compared to Hermitian quantum systems, parity-time-($\mathcal{PT}$-)symmetric non-Hermitian quantum…

Quantum Physics · Physics 2022-09-07 Dong-Xu Chen , Yu Zhang , Jun-Long Zhao , Qi-Cheng Wu , Yu-Liang Fang , Chui-Ping Yang , Franco Nori

Preparation of a non-classically correlated state is the first step of any quantum-enhanced interferometric protocol. An efficient method is the one-axis twisting, which entangles a collection of initially uncorrelated particles by means of…

Quantum Physics · Physics 2015-10-28 K. Gietka , P. Szankowski , T. Wasak , J. Chwedenczuk

Quantum metrology employs quantum resources to enhance the measurement sensitivity beyond that can be achieved classically. While multi-photon entangled NOON states can in principle beat the shot-noise limit and reach the Heisenberg limit,…

Deterministic discrimination of nonorthogonal states is forbidden by quantum measurement theory. However, if we do not want to succeed all the time, i.e. allow for inconclusive outcomes to occur, then unambiguous discrimination becomes…

Quantum Physics · Physics 2009-11-11 Janos Bergou , Ulrike Herzog , Mark Hillery
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