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Related papers: Quantum non-demolition measurements: Concepts, the…

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We characterize the class of quantum measurements that matches the applications of quantum theory to cognition (and decision making) - quantum-like modeling. Projective measurements describe the canonical measurements of the basic…

Artificial Intelligence · Computer Science 2025-12-15 Miho Fuyama , Andrei Khrennikov , Masanao Ozawa

In the scheme of a quantum nondemolition (QND) measurement, an observable is measured without perturbing its evolution. In the context of studies of decoherence in quantum computing, we examine the `open' quantum system of a two-level atom,…

Quantum Physics · Physics 2009-11-13 Subhashish Banerjee , R. Ghosh

In this work we obtain a nondemolition variable for the case in which a charged particle moves in the electric and gravitational fields of a spherical body. Afterwards we consider the continuous monitoring of this nondemolition parameter,…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Abel Camacho , Abel Camacho-Galvan

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

The notion coexistence of quantum observables was introduced to describe the possibility of measuring two or more observables together. Here we survey the various different formalisations of this notion and their connections. We review…

Quantum Physics · Physics 2011-01-04 P. Busch , J. Kiukas , P. Lahti

In Quantum Physics there are circumstances where the direct measurement of particular observables encounters diffculties; in some of these cases, however, its value can be evaluated, i.e. it can be inferred by measuring another observable…

Quantum Physics · Physics 2016-03-23 Giuseppe Nisticò , Angela Sestito

Quantum thermodynamics seeks to extend non-equilibrium stochastic thermodynamics to small quantum systems where non-classical features are essential to its description. Such a research area has recently provided meaningful theoretical and…

We propose a high efficiency tomographic scheme to reconstruct an unknown quantum state of the qubits by using a series of quantum nondemolition (QND) measurements. The proposed QND measurements of the qubits are implemented by probing the…

Quantum Physics · Physics 2015-05-20 J. S. Huang , L. F. Wei , C. H. Oh

Quantum mechanics sets severe limits on the sensitivity and required circulating energy in traditional free-mass gravitational-wave antennas. One possible way to avoid these restrictions is the use of intracavity QND measurements. We…

Quantum Physics · Physics 2009-10-31 Vladimir B. Braginsky , Michael L. Gorodetsky , Farid Ya. Khalili

Quantum metrology promises high-precision measurements of classical parameters with far reaching implications for science and technology. So far, research has concentrated almost exclusively on quantum-enhancements in integrable systems,…

Quantum Physics · Physics 2018-04-16 Lukas J. Fiderer , Daniel Braun

Theory of quantum measurements is often classified as decision theory. An event in decision theory corresponds to the measurement of an observable. This analogy looks clear for operationally testable simple events. However, the situation is…

Quantum Physics · Physics 2015-06-24 V. I. Yukalov , D. Sornette

The applications of spin-based quantum sensors to measurements probing fundamental physics are surveyed. Experimental methods and technologies developed for quantum information science have rapidly advanced in recent years, and these tools…

We exploit geometric properties of quantum states of light in optical cavities to carry out quantum non-demolition measurements. We generalize the 'mode invisibility' method to obtain information about the Wigner function of a squeezed…

Quantum Physics · Physics 2014-10-22 Marvellous Onuma-Kalu , Robert B. Mann , Eduardo Martin-Martinez

Simultaneous measurement of several noncommuting observables is modeled by using semigroups of completely positive maps on an algebra with a non-trivial center. The resulting piecewise-deterministic dynamics leads to chaos and to nonlinear…

Quantum Physics · Physics 2007-05-23 Arkadiusz Jadczyk

We revisit the idea of quantum nondemolition measurement (QND) of optical quanta via a resonantly enhanced Kerr nonlinearity taking into account quantum back action and show that the monolithic microcavities enable QND measurement of number…

Photon detectors are an elementary tool to measure electromagnetic waves at the quantum limit and are heavily demanded in the emerging quantum technologies such as communication, sensing, and computing. Of particular interest is a quantum…

Quantum Physics · Physics 2018-07-04 S. Kono , K. Koshino , Y. Tabuchi , A. Noguchi , Y. Nakamura

We introduce the concept of cloning for classes of observables and classify cloning machines for qubit systems according to the number of parameters needed to describe the class under investigation. A no-cloning theorem for observables is…

Quantum Physics · Physics 2009-11-11 Alessandro Ferraro , Matteo Galbiati , Matteo G. A. Paris

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

We develop a measurement operator formalism to handle quantum nondemolition (QND) measurement induced entanglement generation between two atomic gases. We first derive how the QND entangling scheme reduces to a positive operator-valued…

We present a quantum circuit that implements a non-demolition measurement of complementary single- and bi-partite properties of a two-qubit system: entanglement and single-partite visibility and predictability. The system must be in a pure…

Quantum Physics · Physics 2007-06-20 F. de Melo , S. P. Walborn , János A. Bergou , L. Davidovich
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