English
Related papers

Related papers: Path Integrals over Measurement Amplitudes: Practi…

200 papers

A simple mapping procedure is presented by which classical orbits and path integrals for the motion of a point particle in flat space can be transformed directly into those in curved space with torsion. Our procedure evolved from…

Quantum Physics · Physics 2008-02-03 H. Kleinert

Hybrid quantum-classical systems make it possible to utilize existing quantum computers to their fullest extent. Within this framework, parameterized quantum circuits can be regarded as machine learning models with remarkable expressive…

Quantum Physics · Physics 2019-11-15 Marcello Benedetti , Erika Lloyd , Stefan Sack , Mattia Fiorentini

Quantum metrology and quantum sensing aim to use quantum properties to enhance measurement precision beyond what could be classically achieved. Here, we demonstrate how the analysis of the phase space structure of the classical limit of…

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

Quantum theory allows the traversing of multiple channels in a superposition of different orders. When the order in which the channels are traversed is controlled by an auxiliary quantum system, various unknown parameters of the channels…

Quantum Physics · Physics 2023-09-27 A. Z. Goldberg , L. L. Sanchez-Soto , K. Heshami

We show that recent experiments in hybrid qubit-oscillator devices that measure the phase-space characteristic function of the oscillator via the qubit can be seen through the lens of functional calculus and path integrals, drawing a clear…

Quantum Physics · Physics 2024-11-11 S. Varona , S. Saner , O. Băzăvan , G. Araneda , G. Aarts , A. Bermudez

Quantum phenomena offer the possibility of measuring physical quantities with precision beyond classical limits. However, current progress is constrained by scalability, environmental noise, and challenges in practical integration. This…

Quantum Physics · Physics 2025-10-24 George Mihailescu , Uesli Alushi , Roberto Di Candia , Simone Felicetti , Karol Gietka

A major obstacle to attain the fundamental precision limit of the phase estimation in an interferometry is the identification and implementation of the optimal measurement. Here we demonstrate that this can be accomplished by the use of…

Quantum Physics · Physics 2017-05-10 Wei Zhong , Yixiao Huang , Xiaoguang Wang , Shi-Liang Zhu

High precision interferometers are the building blocks of precision metrology and the ultimate interferometric sensitivity is limited by the quantum noise. Here we propose and experimentally demonstrate a compact quantum interferometer…

Quantum Physics · Physics 2020-05-20 Xiaojie Zuo , Zhihui Yan , Yanni Feng , Jingxu Ma , Xiaojun Jia , Changde Xie , Kunchi Peng

Quantum metrology is supposed to significantly improve the precision of parameter estimation by utilizing suitable quantum resources. However, the predicted precision can be severely distorted by realistic noises. Here, we propose a…

Quantum Physics · Physics 2023-02-15 Yue Zhai , Xiaodong Yang , Kai Tang , Xinyue Long , Xinfang Nie , Tao Xin , Dawei Lu , Jun Li

The radio interferometer measurement equation (RIME), especially in its 2x2 form, has provided a comprehensive matrix-based formalism for describing classical radio interferometry and polarimetry, as shown in the previous three papers of…

Instrumentation and Methods for Astrophysics · Physics 2011-07-06 Oleg M. Smirnov

The outcomes of a series of measurements, made on a quantum system, form a sequence of random events which occur in a particular order. The system, together with a meter or meters, can be seen as following the paths of a stochastic network…

Quantum Physics · Physics 2016-08-01 D. Sokolovski

The effect of Planck scale quantum geometrical effects on measurements with interferometers is estimated with standard physics, and with a variety of proposed extensions. It is shown that effects are negligible in standard field theory with…

General Relativity and Quantum Cosmology · Physics 2016-06-28 Ohkyung Kwon , Craig J. Hogan

We define syntax and semantics of quantum circuits, allowing measurement gates and classical channels. We define circuit-based quantum algorithms and prove that, semantically, any such algorithm is equivalent to a single measurement that…

Quantum Physics · Physics 2021-07-20 Yuri Gurevich , Andreas Blass

We present an innovative optical imaging system for measuring parameters of a small particle such as a macromolecule or nanoparticle at the quantum limit of sensitivity. In comparison to the conventional confocal interferometric scattering…

Quantum Physics · Physics 2025-07-14 Fabian Müller , Emre Köse , Alfred J. Meixner , Erik Schäffer , Daniel Braun

We introduce a framework for the formal specification and verification of quantum circuits based on the Feynman path integral. Our formalism, built around exponential sums of polynomial functions, provides a structured and natural way of…

Quantum Physics · Physics 2019-01-30 Matthew Amy

Parametric quantum circuits play a crucial role in the performance of many variational quantum algorithms. To successfully implement such algorithms, one must design efficient quantum circuits that sufficiently approximate the solution…

Quantum Physics · Physics 2021-05-05 Lena Funcke , Tobias Hartung , Karl Jansen , Stefan Kühn , Paolo Stornati

Mensky has suggested to account for "continuous measurement" by attaching to a path integral a weight function centered around the classical path that the integral assigns a probability amplitude to. We show that in fact this weight…

Mathematical Physics · Physics 2014-12-31 Roman Sverdlov , Luca Bombelli

Measurement of a charge qubit via point contacts with complex internal structures is considered. In this context, a fully formalized derivation of the many-body wave function method is presented, together with the corresponding master…

Mesoscale and Nanoscale Physics · Physics 2025-10-13 George Stavisskii , Leonid Fedichkin

Starting from the Hamilton-Jacobi equation describing a classical ensemble, one may infer a quantum dynamics using the principle of maximum uncertainty. That procedure requires an appropriate measure of uncertainty: Such a measure is…

Quantum Physics · Physics 2009-11-10 Rajesh R. Parwani