English
Related papers

Related papers: Coupling-Deformed Pointer Observables and Weak Val…

200 papers

The influence of outside quantum noises on the amplification of weak measurements is investigated. Three typical quantum noises are discussed. The maximum values of the pointer's shifts decrease sharply with the strength of the depolarizing…

Quantum Physics · Physics 2015-05-11 Xuanmin Zhu , Yu-Xiang Zhang

We investigate the estimation of a small interaction parameter from the outcomes of weak quantum measurements implemented by the interaction. The relation of weak values and sensitivity is explained and the different contributions of…

Quantum Physics · Physics 2012-10-23 Holger F. Hofmann , Michael E. Goggin , Marcelo P. Almeida , Marco Barbieri

Recent empirical work in the field of 'weak measurements' has yielded novel ways of more directly accessing and exploring the quantum wavefunction. Measuring either position or momentum for a photon in a 'weak' manner yields a wide range of…

Quantum Physics · Physics 2013-06-17 David R Geelan

Measurements are crucial in quantum mechanics, in fundamental research as well as in applicative fields like quantum metrology, quantum-enhanced measurements and other quantum technologies. In the recent years, weak-interaction-based…

The exact conditions on valid pointer states for weak measurements are derived. It is demonstrated that weak measurements can be performed with any pointer state with vanishing probability current density. This condition is found both for…

Quantum Physics · Physics 2009-11-10 Lars M. Johansen

Weak values arise in quantum theory when the result of a weak measurement is conditioned on a subsequent strong measurement. The majority of the trials are discarded, leaving only very few successful events. Intriguingly those can display a…

Quantum Physics · Physics 2016-05-19 George C. Knee , Joshua Combes , Christopher Ferrie , Erik M. Gauger

In a weak measurement with post-selection, a measurement value, called the weak value, can be amplified beyond the eigenvalues of the observable. However, there are some controversies whether the weak value amplification is practically…

Quantum Physics · Physics 2015-09-30 Atsushi Nishizawa

Weak measurement with a coherent state pointer and in combination with an orthogonal postselection can lead to a surprising amplification effect, and we give a fire-new physical mechanism about the weak measurement in order to understand…

Quantum Physics · Physics 2015-09-03 Gang Li , Ming-Yong Ye , Xiu-Min Lin , He-Shan Song

In the weak measurement (WM) scenario involving weak interaction and postselection by projective measurement, the empirical significance of weak values is manifested in terms of shifts in the measurement pointer's mean position and mean…

Quantum Physics · Physics 2016-11-18 Som Kanjilal , Girish Muralidhara , Dipankar Home

We consider weakly coupled LQ optimal control problems and derive estimates on the sensitivity of the optimal value function in dependence of the coupling strength. In order to improve these sensitivity estimates a "coupling adapted" norm…

Optimization and Control · Mathematics 2014-04-22 Péter Koltai , Oliver Junge

We analyze the average of weak values over statistical ensembles of pre- and post-selected states. The protocol of weak values, proposed by Aharonov et al., is the result of a weak measurement conditional on the outcome of a subsequent…

Mesoscale and Nanoscale Physics · Physics 2010-01-18 Alessandro Romito , Yuval Gefen

We propose a protocol for a controlled experiment to measure a weak value of the electron's spin in a solid state device. The weak value is obtained by a two step procedure -- weak measurement followed by a strong one (post-selection),…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Alessandro Romito , Yuval Gefen , Yaroslav M. Blanter

We extend the idea of weak measurements to the general case, provide a complete treatment and obtain results for both the regime when the pre-selected and post-selected states (PPS) are almost orthogonal and the regime when they are exactly…

Quantum Physics · Physics 2015-03-17 Shengjun Wu , Yang Li

The AAV effect is the well-known phenomenon where a weak measurement followed by post-selection leads to a pointer shift proportional to the weak value of the measured observable. The effect is usually derived by considering a perturbative…

Quantum Physics · Physics 2014-06-04 Jeff Z. Salvail

The weak value, the average result of a weak measurement, has proven useful for probing quantum and classical systems. Examples include the amplification of small signals, investigating quantum paradoxes, and elucidating fundamental quantum…

Quantum Physics · Physics 2019-12-24 A. Hariri , D. Curic , L. Giner , J. S. Lundeen

Weak measurement is an important technique for detecting the tiny spin-dependent splitting in photonic spin Hall effect. The weak measurement is only valid when the probe wavefunction remains almost undisturbed during the procedure of…

Optics · Physics 2015-05-19 Shizhen Chen , Xinxing Zhou , Chengquan Mi , Hailu Luo , Shuangchun Wen

Weak measurements offer new insights into the behavior of quantum systems. Combined with post-selection, quantum mechanics predicts a range of new experimentally testable phenomena. In this paper I consider weak measurements performed on…

Quantum Physics · Physics 2009-11-13 P. C. W. Davies

Post-selection strategies have been proposed with the aim of amplifying weak signals, which may help to overcome detection thresholds associated with technical noise in high-precision measurements. Here we use an optical setup to…

Quantum Physics · Physics 2017-01-11 G. Bié Alves , A. Pimentel , M. Hor-Meyll , S. P. Walborn , L. Davidovich , R. L. de Matos Filho

Closed expressions are derived for the quantum measurement statistics of pre-and postselected gaussian particle beams. The weakness of the pre-selection step is shown to compete with the non-orthogonality of post-selection in a transparent…

Quantum Physics · Physics 2010-04-14 Tamas Geszti

In a weak measurement, the average output $\langle o\rangle$ of a probe that measures an observable $\hat{A}$ of a quantum system undergoing both a preparation in a state $\rho_i$ and a postselection in a state $E_\mathrm{f}$ is, to a good…

Quantum Physics · Physics 2014-05-02 Antonio Di Lorenzo