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Related papers: Quantum states made to measure

200 papers

We point out a general framework that encompasses most cases in which quantum effects enable an increase in precision when estimating a parameter (quantum metrology). The typical quantum precision-enhancement is of the order of the square…

Quantum Physics · Physics 2009-11-11 Vittorio Giovannetti , Seth Lloyd , Lorenzo Maccone

We present an improved phase estimation scheme employing entangled coherent states and demon- strate that the states give the smallest variance in the phase parameter in comparison to NOON, BAT and "optimal" states under perfect and lossy…

Quantum Physics · Physics 2011-11-30 Jaewoo Joo , William J. Munro , Timothy P. Spiller

Quantum computation offers a promising new kind of information processing, where the non-classical features of quantum mechanics can be harnessed and exploited. A number of models of quantum computation exist, including the now well-studied…

Quantum Physics · Physics 2011-08-03 H. J. Briegel , D. E. Browne , W. Dür , R. Raussendorf , M. Van den Nest

The purpose of quantum technologies is to explore how quantum effects can improve on existing solutions for the treatment of information. Quantum photonics sensing holds great promises for reaching a more efficient trade-off between…

Quantum Physics · Physics 2025-07-31 Marco Barbieri

We explore the sense in which the state of a physical system may or may not be regarded (an) observable in quantum mechanics. Simple and general arguments from various lines of approach are reviewed which demonstrate the following no-go…

Quantum Physics · Physics 2007-05-23 P. Busch

Quantum metrology enhances measurement precision by utilising the properties of quantum physics. In interferometry, this is typically achieved by evolving highly-entangled quantum states before performing single-shot measurements to reveal…

Quantum Physics · Physics 2023-01-11 Kawthar Al Rasbi , Almut Beige , Lewis A. Clark

In this paper we present a search algorithm that finds useful optical quantum states which can be created with current technology. We apply the algorithm to the field of quantum metrology with the goal of finding states that can measure a…

Quantum Physics · Physics 2016-08-03 P. A. Knott

When applied to practical problems, the very laws of quantum mechanics can provide a unique resource to beat the limits imposed by classical physics: this is the case of quantum metrology and high-precision sensing. Here we review the main…

Quantum Physics · Physics 2018-06-07 Stefano Olivares

Sensing and metrology play an important role in fundamental science and applications, by fulfilling the ever-present need for more precise data sets, and by allowing to make more reliable conclusions on the validity of theoretical models.…

Quantum Physics · Physics 2021-03-23 S. Danilin , M. Weides

The problem of measurement in quantum mechanics is reanalyzed within a general, strictly probabilistic framework (without reduction postulate). Based on a novel comprehensive definition of measurement the natural emergence of objective…

Quantum Physics · Physics 2007-05-23 Markus Simonius

Quantum theory is incredibly successful, explaining the microscopic world with great accuracy, from the behaviour of subatomic particles to chemical reactions to solid-state electronics. There is not a single experimental finding…

Quantum Physics · Physics 2021-04-07 James Millen , Benjamin A. Stickler

In a quantum system that is bounded by past and future conditions, weak continuous monitoring forward-evolving and backward-evolving quantum states are usually carried out separately. Therefore, measured signals at a given time t cannot be…

Quantum Physics · Physics 2019-05-20 Le Bin Ho

Quantum metrology research promises approaches to build new sensors that achieve the ultimate level of precision measurement and perform fundamentally better than modern sensors. Practical schemes that tolerate realistic fabrication…

Quantum optical Gaussian states are a type of important robust quantum states which are manipulatable by the existing technologies. So far, most of the important quantum information experiments are done with such states, including bright…

Quantum Physics · Physics 2009-11-13 X. -B. Wang , T. Hiroshima , A. Tomita , M. Hayashi

The simultaneous quantum estimation of multiple parameters can provide a better precision than estimating them individually. This is an effect that is impossible classically. We review the rich background of multi-parameter quantum…

Quantum Physics · Physics 2016-09-28 Magdalena Szczykulska , Tillmann Baumgratz , Animesh Datta

We present a framework for relativistic quantum metrology that is useful for both Earth-based and space-based technologies. Quantum metrology has been so far successfully applied to design precision instruments such as clocks and sensors…

Quantum Physics · Physics 2014-05-23 Mehdi Ahmadi , David Edward Bruschi , Carlos Sabín , Gerardo Adesso , Ivette Fuentes

We discuss single adaptive measurements for the estimation of mixed quantum states of qubits. The results are compared to the optimal estimation schemes using collective measurements. We also demonstrate that the advantage of collective…

Quantum Physics · Physics 2009-11-06 Dietmar G. Fischer , Matthias Freyberger

There are new detector proposals and R&D that utilize quantum enhancements not previously adopted. Examples include superconducting quantum sensors, atom interferometry, and quantum spin sensors. They are mainly motivated by industrial…

Instrumentation and Detectors · Physics 2025-08-15 Masashi Hazumi

A many-body atomic system coupled to quantized light is subject to weak measurement. Instead of coupling light to the on-site density, we consider the quantum backaction due to the measurement of matter-phase-related variables such as…

Quantum Physics · Physics 2017-02-27 Wojciech Kozlowski , Santiago F. Caballero-Benitez , Igor B. Mekhov

A phase space mathematical formulation of quantum mechanical processes accompanied by and ontological interpretation is presented in an axiomatic form. The problem of quantum measurement, including that of quantum state filtering, is…

Quantum Physics · Physics 2015-06-26 Daniela Dragoman