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Related papers: Observable-projected ensembles

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We propose a new class of probabilistic reversing operations on the state of a system that was disturbed by a weak measurement. It can approximately recover the original state from the disturbed state especially with an additional…

Quantum Physics · Physics 2010-09-01 Hiroaki Terashima , Masahito Ueda

In quantum thermodynamics, the standard approach to estimate work fluctuations in unitary processes is based on two projective measurements, one performed at the beginning of the process and one at the end. The first measurement destroys…

Quantum Physics · Physics 2019-03-07 Kang-Da Wu , Yuan Yuan , Guo-Yong Xiang , Chuan-Feng Li , Guang-Can Guo , Martí Perarnau-Llobet

We consider the optical generation and verification of entanglement in atomic ensembles under non-uniform interaction between the ensemble and an optical mode. We show that for a wide range of parameters a system of non-uniformly coupled…

Quantum Physics · Physics 2016-01-20 Jiazhong Hu , Wenlan Chen , Zachary Vendeiro , Hao Zhang , Vladan Vuletić

A critical requirement for diverse applications in Quantum Information Science is the capability to disseminate quantum resources over complex quantum networks. For example, the coherent distribution of entangled quantum states together…

Quantum Physics · Physics 2009-11-11 C. W. Chou , H. de Riedmatten , D. Felinto , S. V. Polyakov , S. J. van Enk , H. J. Kimble

The process tensor provides a general representation of a quantum system evolving under repeated interventions and is fundamental for numerical simulations of local many-body dynamics. In this work, we introduce the projected process…

Quantum Physics · Physics 2026-05-18 Peter O'Donovan , Neil Dowling , Kavan Modi , Mark T. Mitchison

The resources needed to conventionally characterize a quantum system are overwhelmingly large for high- dimensional systems. This obstacle may be overcome by abandoning traditional cornerstones of quantum measurement, such as general…

Quantum Physics · Physics 2016-05-17 Gregory A. Howland , Samuel H. Knarr , James Schneeloch , Daniel J. Lum , John C. Howell

Multiparty quantum states are useful for a variety of quantum information and computation protocols. We define a multiparty entanglement measure based on local measurements on a multiparty quantum state, and an entanglement measure averaged…

"Weak measurements" -- involving a weak unitary interaction between a quantum system and a meter followed by a projective measurement -- are investigated when the system has a non-Hermitian Hamiltonian. We show in particular how the…

Quantum Physics · Physics 2012-12-21 A. Matzkin

The polarization analysis of quantized probe light transmitted through an atomic ensemble has been used to prepare entangled collective atomic states. In a "balanced" detection configuration, where the difference signal from two detection…

Quantum Physics · Physics 2009-11-11 C. Genes P. R. Berman

It is revealed that ensembles consisting of multipartite quantum states can exhibit different kinds of nonlocalities. An operational measure is introduced to quantify nonlocalities in ensembles consisting of bipartite quantum states.…

Quantum Physics · Physics 2015-05-13 Ming-Yong Ye , Yan-Kui Bai , Xiu-Min Lin , Z. D. Wang

For a given pure state of a composite quantum system we analyze the product of its projections onto a set of locally orthogonal separable pure states. We derive a bound for this product analogous to the entropic uncertainty relations. For…

Quantum Physics · Physics 2015-05-28 Łukasz Rudnicki , Paweł Horodecki , Karol Życzkowski

The present work proposes the concept of induced percolation over multiple-object systems, so that features such as the number of merged clusters can be used as a relevant measurement. The suggested approach involves the expansion of the…

Disordered Systems and Neural Networks · Physics 2007-05-23 Luciano da Fontoura Costa

This paper presents simulations of the state vector dynamics for a pair of atomic samples which are being probed by phase shift measurements on an optical beam passing through both samples. We show how measurements, which are sensitive to…

Quantum Physics · Physics 2016-09-08 Antonio Di Lisi , Klaus Moelmer

Complete measurement of a quantum observable (POVM) is a measurement of the maximally refined version of the POVM. Complete measurements give information on multiplicities of measurement outcomes and can be viewed as state preparation…

Quantum Physics · Physics 2015-06-05 Juha-Pekka Pellonpää

Quantum thermalization in a many-body system is defined by the approach of local subsystems towards a universal form, describable as an ensemble of quantum states wherein observables acquire thermal expectation values. Recently, it was…

Quantum Physics · Physics 2023-09-19 Matteo Ippoliti , Wen Wei Ho

We consider an experiment in which quantum tomography data is collected before and after an entangling measurement performed on two independently prepared, maximally-mixed ensembles. We show that each sub-ensemble that is, as expected,…

Quantum Physics · Physics 2014-06-24 D. J. Miller , Matt Farr

The standard approach to quantum measurements is to assume that they lead to effectively instantaneous collapse of the quantum state. However, if we assume that we are unable to enforce at what exact moment of time the measurement occurs…

Quantum Physics · Physics 2026-03-20 Igor Prlina , Milutin Živković

Observational entropy is interpreted as the uncertainty an observer making measurements associates with a system. So far, properties that make such an interpretation possible rely on the assumption of ideal projective measurements. We show…

Quantum Physics · Physics 2023-12-11 Dominik Šafránek , Juzar Thingna

The existence of incompatibility is one of the most fundamental features of quantum theory, and can be found at the core of many of the theory's distinguishing features, such as Bell inequality violations and the no-broadcasting theorem. A…

Quantum Physics · Physics 2018-06-27 Sergey N. Filippov , Teiko Heinosaari , Leevi Leppäjärvi

We report an experimental investigation of the role of measurement in quantum metrology when the states of the probes are mixed. In particular, we investigated optimized local measurements and general global projective measurements,…

Quantum Physics · Physics 2021-02-22 R. S. Piera , S. P. Walborn , G. H. Aguilar