English
Related papers

Related papers: Estimating the post-measurement state

200 papers

The sets of after-measurement states for standard and generalized quantum measurements are compared. It is shown that for a SIC-POVM generalized measurement, the ratio of the volume of the set of after-measurement states and the volume of…

Quantum Physics · Physics 2010-08-05 I. D. Ivanovic

Various forms of optimality for quantum observables described as normalized positive operator valued measures (POVMs) are studied in this paper. We give characterizations for observables that determine the values of the measured quantity…

Quantum Physics · Physics 2018-09-28 Erkka Haapasalo , Juha-Pekka Pellonpaa

The standard approach to quantum measurement discrimination is to perform the given unknown measurement on a probe state, possibly entangled with an auxiliary system, and make a decision based on the measurement outcome obtained. In this…

Quantum Physics · Physics 2026-02-25 Charbel Eid , Marco Túlio Quintino

We define a complete measurement of a quantum observable (POVM) as a measurement of the maximally refined version of the POVM. Complete measurements give information from the multiplicities of the measurement outcomes and can be viewed as…

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

Quantum fidelity is a measure to quantify the closeness of two quantum states. In an operational sense, it is defined as the minimal overlap between the probability distributions of measurement outcomes and the minimum is taken over all…

Quantum Physics · Physics 2019-07-24 Changhun Oh , Changhyoup Lee , Leonardo Banchi , Su-Yong Lee , Carsten Rockstuhl , Hyunseok Jeong

We describe a technique for self consistently characterizing both the quantum state of a single qubit system, and the positive-operator-valued measure (POVM) that describes measurements on the system. The method works with only ten…

Quantum Physics · Physics 2021-07-28 A. Stephens , J. M. Cutshall , T. McPhee , M. Beck

Quantum coherence with respect to orthonormal bases has been studied extensively in the past few years. Recently, Bischof, et al. [Phys. Rev. Lett. 123, 110402 (2019)] generalized it to the case of general positive operator-valued measure…

Quantum Physics · Physics 2020-07-21 Jianwei Xu , Lian-He Shao , Shao-Ming Fei

The discrimination of quantum states is a central problem in quantum information science and technology. Meanwhile, partial post-selection has emerged as a valuable tool for quantum state engineering. In this work, we bring these two areas…

Quantum Physics · Physics 2026-04-14 Qipeng Qian , Christos N. Gagatsos

We present a universal algorithm for the optimal quantum state estimation of an arbitrary finite dimensional system. The algorithm specifies a physically realizable positive operator valued measurement (POVM) on a finite number of…

Quantum Physics · Physics 2009-10-30 Radoslav Derka , Vladimir Buzek , Artur Ekert

Given an unknown state of a qudit that has already been measured optimally, can one still extract any information about the original unknown state? Clearly, after a maximally informative measurement, the state of the system `collapses' into…

Quantum Physics · Physics 2011-09-26 Peter Rapcan , John Calsamiglia , Ramon Munoz-Tapia , Emilio Bagan , Vladimir Buzek

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

We introduce and implement a technique to extend the quantum computational power of cluster states by replacing some projective measurements with generalized quantum measurements (POVMs). As an experimental demonstration we fully realize an…

A direct derivation is given for the optimal mean fidelity of quantum state estimation of a d-dimensional unknown pure state with its N copies given as input, which was first obtained by M. Hayashi in terms of an infinite set of covariant…

Quantum Physics · Physics 2009-11-10 A. Hayashi , T. Hashimoto , M. Horibe

We investigate the optimal estimation of quantum expectation value of a physical observable, which minimizes a mean error with respect to general measure of deviation, when a finite number of copies of a pure state are prepared. If pure…

Quantum Physics · Physics 2007-05-23 Minoru Horibe , Akihisa Hayashi , Takaaki Hashimoto

We quantify the disturbance of a quantum state undergoing a sequence of observations, and particularly focus on a weak measurement followed by post-selection and compare these results to the projective counterpart. Taking into account the…

Quantum Physics · Physics 2021-01-04 Philipp Stammer

When quantum states are used to send classical information, the receiver performs a measurement on the signal states. The amount of information extracted is often not optimal due to the receiver's measurement scheme and experimental…

Quantum Physics · Physics 2018-04-25 Rui Han , Gerd Leuchs , Markus Grassl

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

Generalized measurement schemes on one part of bipartite states, which would leave the set of all separable states insensitive are explored here to understand quantumness of correlations in a more general perspecitve. This is done by…

Quantum Physics · Physics 2012-01-04 A. R. Usha Devi , A. K. Rajagopal , Sudha

Studying sequential measurements is of the utmost importance to both the foundational aspects of quantum theory and the practical implementations of quantum technologies, with both of these applications being abstractly described by the…

Quantum Physics · Physics 2022-03-01 Leevi Leppäjärvi , Michal Sedlák

Obtaining information from a quantum system through a measurement typically disturbs its state. The postmeasurement states for a given measurement, however, are not unique and highly rely on the chosen measurement model, complicating the…

Quantum Physics · Physics 2024-01-04 Nayere Saberian , Seyed Javad Akhtarshenas , Fereshte Shahbeigi
‹ Prev 1 2 3 10 Next ›