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Related papers: Weak values from path integrals

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We generalize the concept of a weak value of a quantum observable to cover arbitrary real positive operator measures. We show that the definition is operationally meaningful in the sense that it can be understood within the quantum theory…

Quantum Physics · Physics 2013-05-29 Erkka Haapasalo , Pekka Lahti , Jussi Schultz

Feynman proposed a postulate or a method of quantization in his celebrated paper in 1948. Applying Feynman's postulate to temporally continuous quantum measurements of the positions of particles, Mensky proposed the restricted Feynman path…

Mathematical Physics · Physics 2023-11-27 Wataru Ichinose

The one-sided bouncer and the symmetric bouncer involve a one-dimensional particle in a piecewise linear potential. For such problems, the time-dependent quantum mechanical propagator cannot be found in closed form. The semiclassical…

Quantum Physics · Physics 2021-09-29 Yen Lee Loh , Chee Kwan Gan

A quantum measurement model based upon restricted path-integrals allows us to study measurements of generalized position in various one-dimensional systems of phenomenological interest. After a general overview of the method we discuss the…

Quantum Physics · Physics 2008-02-03 Tommaso Calarco , Roberto Onofrio , Carlo Presilla , Lorenza Viola

The readings of a highly inaccurate "weak" quantum meter, employed to determine the value of a dichotomous variable $S$ without destroying the interference between the alternatives,may take arbitrary values. We show that the expected values…

Quantum Physics · Physics 2015-09-17 D. Sokolovski

A so called 'weak value' of an observable in quantum mechanics (QM) may be obtained in a weak measurement + post-selection procedure on the QM system under study. Applied to number operators, it has been invoked in revisiting some QM…

Quantum Physics · Physics 2015-06-12 Bengt E Y Svensson

Discretizations of the Feynman-Kac path integral representation of the quantum mechanical density matrix are investigated. Each infinite-dimensional path integral is approximated by a Riemann integral over a finite-dimensional function…

Statistical Mechanics · Physics 2007-05-23 Stephen D. Bond , Brian B. Laird , Benedict J. Leimkuhler

Many quantum paradoxes based on a realistic view of weak values were discussed in the last decades. They lead to astonishing conclusions such as the measurement of a spin component of a spin-1/2 particle resulting in $100\hbar$, the…

Quantum Physics · Physics 2024-03-15 Alice M. Aredes , Pablo L. Saldanha

Weak measurements may result in extra quantity of quantumness of correlations compared with standard projective measurement on a bipartite quantum state. We show that the quantumness of correlations by weak measurements can be consumed for…

Quantum Physics · Physics 2014-03-18 Lin-Ping Huai , Bo Li , Shi-Xian Qu , Heng Fan

In this work we revisit the important and controversial concept of quantum weak values, aiming to provide a simplified understanding to its associated physics and the origin of anomaly. Taking the Stern-Gerlach setup as a working system, we…

Quantum Physics · Physics 2016-02-29 Lupei Qin , Wei Feng , Xin-Qi Li

Using the quantum transition path time probability distribution we show that time averaging of weak values leads to unexpected results. We prove a weak value time energy uncertainty principle and time energy commutation relation. We also…

Quantum Physics · Physics 2018-09-05 Eli Pollak , S. Miret-Artés

The weak value of a variable O is a description of an effective interaction with that variable in the limit of weak coupling. It is particularly important for a pre- and post-selected quantum system.

Quantum Physics · Physics 2007-06-12 Lev Vaidman

We study certain aspects of the effective, occasionally called collective, description of complex quantum systems within the framework of the path integral formalism, in which the environment is integrated out. Generalising the standard…

Statistical Mechanics · Physics 2007-05-23 U. Eckern , M. J. Gruber , P. Schwab

Vaidman, in a recent article adopts the method of 'quantum weak measurements in pre- and postselected ensembles' to ascertain whether or not the chained-Zeno counterfactual computation scheme proposed by Hosten et al. is counterfactual;…

Quantum Physics · Physics 2007-05-23 Onur Hosten , Paul G. Kwiat

In this study, we study weak values from a quantum-logical viewpoint. In addition, we examine the validity of the counterfactual statements of Hardy's paradox, which are based on weak values, and we show that these statements have not been…

Quantum Physics · Physics 2013-07-23 Riuji Mochizuki

The operational definition of a weak value for a quantum mechanical system involves the limit of the weak measurement strength tending to zero. I study how this limit compares to the situation for the undisturbed (no weak measurement)…

Quantum Physics · Physics 2015-10-26 B. E. Y. Svensson

The fact that not all quantum observables are jointly measurable is one of the major differences between quantum and classical theory. In the former, non-commuting observables can only be simultaneously measured with limited precision. We…

Quantum Physics · Physics 2016-10-17 Gilles Pütz , Tomer Barnea , Nicolas Gisin , Anthony Martin

We derive the weak value deflection given in a paper by Dixon et al. (Phys. Rev. Lett. 102, 173601 (2009)) both quantum mechanically and classically. This paper is meant to cover some of the mathematical details omitted in that paper owing…

The extraordinary concept of weak value amplification has attracted considerable attention for addressing foundational questions in quantum mechanics and for metrological applications in high precision measurement of small physical…

The formalism of weak measurement in quantum mechanics has revealed profound connections between measurement theory, quantum foundations, and signal processing. In this paper, we develop a pointer-free derivation of superoscillations,…

Quantum Physics · Physics 2025-08-04 Mirco A. Mannucci