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Related papers: Unambiguous quantum state filtering

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Intrinsic randomness is generated when a quantum state is measured in any basis in which it is not diagonal. In an adversarial scenario, we quantify this randomness by the probability that a correlated eavesdropper could correctly guess the…

Quantum Physics · Physics 2026-02-19 Fionnuala Curran

In this report, we present a framework for implementing an arbitrary $n$-outcome generalized quantum measurement (POVM) on an $m$-qubit register as a sequence of two-outcome measurements requiring only single ancillary qubit. Our procedure…

Quantum Physics · Physics 2024-07-16 Daniel Reitzner , Jan Bouda

The quantum formalism permits one to discriminate sometimes between any set of linearly-independent pure states with certainty. We obtain the maximum probability with which a set of equally-likely, symmetric, linearly-independent states can…

Quantum Physics · Physics 2009-10-31 Anthony Chefles , Stephen M. Barnett

A core principle of quantum theory is that non-orthogonal quantum states cannot be perfectly distinguished with single-shot measurements. However, it is possible to exclude a subset of non-orthogonal states without error in certain…

We discuss a possibility to build a programmable quantum measurement device (a "quantum multimeter"). That is, a device that would be able to perform various desired generalized, positive operator value measure (POVM) measurements depending…

Quantum Physics · Physics 2013-05-29 Miloslav Dusek , Vladimir Buzek

We investigate generalized measurements, based on positive-operator-valued measures, and von Neumann measurements for the unambiguous discrimination of two mixed quantum states that occur with given prior probabilities. In particular, we…

Quantum Physics · Physics 2009-11-11 Ulrike Herzog , Janos A. Bergou

We propose and experimentally demonstrate non-destructive and noiseless removal (filtering) of vacuum states from an arbitrary set of coherent states of continuous variable systems. Errors i.e. vacuum states in the quantum information are…

Quantum Physics · Physics 2009-11-13 C. Wittmann , D. Elser , U. L. Andersen , R. Filip , P. Marek , G. Leuchs

The problem of unambiguously distinguishing among nonorthogonal but linearly independent quantum states can be solved by mapping the set of nonorthogonal quantum states onto a set of orthogonal ones, which can then be distinguished without…

Quantum Physics · Physics 2009-11-06 Yuqing Sun , Mark Hillery , Janos Bergou

Quantum mechanics forbids deterministic discrimination among non-orthogonal states. Nonetheless, the capability to distinguish nonorthogonal states unambiguously is an important primitive in quantum information processing. In this work, we…

Quantum Physics · Physics 2016-08-16 Masoud Mohseni , Aephraim M. Steinberg , János A. Bergou

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

We address the problem of distinguishing among a finite collection of quantum states, when the states are not entirely known. For completely specified states, necessary and sufficient conditions on a quantum measurement minimizing the…

Quantum Physics · Physics 2009-11-11 Noam Elron , Yonina C. Eldar

Generalized quantum measurements identifying non-orthogonal states without ambiguity often play an indispensable role in various quantum applications. For such unambiguous state discrimination scenario, we have a finite probability of…

Quantum Physics · Physics 2021-04-16 Shuro Izumi , Jonas S. Neergaard-Nielsen , Ulrik L. Andersen

The goal of comparison is to reveal the difference of compared objects as fast and reliably as possible. In this paper we formulate and investigate the unambiguous comparison of unknown quantum measurements represented by non-degenerate…

Quantum Physics · Physics 2009-11-13 Mario Ziman , Teiko Heinosaari , Michal Sedlak

We consider the probability by which quantum phase measurements of a given precision can be done successfully. The least upper bound of this probability is derived and the associated optimal state vectors are determined. The probability…

Quantum Physics · Physics 2009-02-14 Thomas Schürmann

In this paper, we consider the problem of unambiguous discrimination between a set of mixed quantum states. We first divide the density matrix of each mixed state into two parts by the fact that it comes from ensemble of pure quantum…

Quantum Physics · Physics 2007-05-23 Chi Zhang , Yuan Feng , Ming Sheng Ying

The objective of this work is to develop a recursive, discrete time quantum filtering equation for a system that interacts with a probe, on which measurements are performed according to the Positive Operator Valued Measures (POVMs)…

Quantum Physics · Physics 2013-09-10 Ram A. Somaraju , Alain Sarlette , Hugo Thienpont

Extracting information from quantum devices has long been a crucial problem in the field of quantum mechanics. By performing elaborate measurements, quantum state tomography, an important and fundamental tool in quantum science and…

Quantum Physics · Physics 2022-06-24 Yu Wang , Keren Li

In this article, we study the problem of comparing mixed quantum states: given $n$ unknown mixed quantum states, can one determine whether they are identical or not with an unambiguous quantum measurement? We first study universal…

Quantum Physics · Physics 2015-05-18 Shengshi Pang , Shengjun Wu

Quantum hypothesis testing is an important tool for quantum information processing. Two main strategies have been widely adopted: in a minimum error discrimination strategy, the average error probability is minimized; while in an…

Quantum Physics · Physics 2020-11-25 Quntao Zhuang

We derive the optimal measurement for quantum state discrimination without a priori probabilities, i.e. in a minimax strategy instead of the usually considered Bayesian one. We consider both minimal-error and unambiguous discrimination…

Quantum Physics · Physics 2025-04-02 Giacomo Mauro D'Ariano , Massimiliano Federico Sacchi , Jonas Kahn