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Related papers: Measuring Non-Hermitian Operators via Weak Values

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Quantum theory allows direct measurement of the average of a non-Hermitian operator using the weak value of the positive semidefinite part of the non-Hermitian operator. Here, we experimentally demonstrate the measurement of weak value and…

Quantum Physics · Physics 2019-02-20 Gaurav Nirala , Surya Narayan Sahoo , Arun K Pati , Urbasi Sinha

A non-commuting measurement transfers, via the apparatus, information encoded in a system's state to the external "observer". Classical measurements determine properties of physical objects. In the quantum realm, the very same notion…

Quantum Physics · Physics 2016-08-31 Bartłomiej Gardas , Sebastian Deffner , Avadh Saxena

Observables are believed that they must be Hermitian in quantum theory. Based on the obviously physical fact that only eigenstates of observable and its corresponding probabilities, i.e., spectrum distribution of observable are actually…

Quantum Physics · Physics 2017-01-06 Meng-Jun Hu , Xiao-Min Hu , Yong-Sheng Zhang

Non-Hermitian dynamics in quantum systems have unveiled novel phenomena, yet the implementation of valid non-Hermitian quantum measurement remains a challenge, because a universal quantum projective mechanism on the complete but skewed…

In quantum mechanics, predictions are made by way of calculating expectation values of observables, which take the form of Hermitian operators. It is far less common to exploit non-Hermitian operators to perform measurements. Here, we show…

Quantum Physics · Physics 2015-11-04 Eliot Bolduc , Genevieve Gariepy , Jonathan Leach

Quantum measurement is one of the most fascinating and discussed phenomena in quantum physics, due to the impact on the system of the measurement action and the resulting interpretation issues. Scholars proposed weak measurements to amplify…

Quantum Physics · Physics 2024-01-23 Lorena Ballesteros Ferraz , Riccardo Muolo , Yves Caudano , Timoteo Carletti

Weak values have been shown to be helpful especially when considering them as the outcomes of weak measurements. In this paper we show that in principle, the real and imaginary parts of the weak value of any operator may be elucidated from…

Quantum Physics · Physics 2018-10-17 Eliahu Cohen , Eli Pollak

During the recent developments of quantum theory it has been clarified that the observable quantities (like energy or position) may be represented by operators (with real spectra) which are manifestly non-Hermitian. The mathematical…

The evaluation of uncertainties in quantum measurements is problematic since the correct value of an observable between state preparation and measurement is experimentally inaccessible. In Ozawa's formulation of uncertainty relations for…

Quantum Physics · Physics 2012-05-02 Holger F. Hofmann

Uncertainty relations for Hermitian operators have been confirmed through many experiments. However, previous experiments have only tested the special case of non-Hermitian operators, i.e., uncertainty relations for unitary operators. In…

Quantum Physics · Physics 2025-08-19 Xinzhi Zhao , Xinglei Yu , Wenting Zhou , Chengjie Zhang , Jin-Shi Xu , Chuan-Feng Li , Guang-Can Guo

It is the purpose of the present contribution to demonstrate that the generalization of the concept of a quantum mechanical observable from the Hermitian operator of standard quantum mechanics to a positive operator-valued measure is not a…

Quantum Physics · Physics 2017-08-23 Willem M. de Muynck

This paper presents the measurement problem from the point of view of the thermal interpretation of quantum physics introduced in Part II. The measurement of a Hermitian quantity $A$ is regarded as giving an uncertain value approximating…

Quantum Physics · Physics 2019-04-25 Arnold Neumaier

In contrast to a projective quantum measurement in which the system is projected onto an eigenstate of the measured operator, in a weak measurement the system is only weakly perturbed while only partial information on the measured…

Quantum Physics · Physics 2018-10-26 Maicol A. Ochoa , Wolfgang Belzig , Abraham Nitzan

The relevance in Physics of non-Hermitian operators with real eigenvalues is being widely recognized not only in quantum mechanics but also in other areas, such as quantum optics, quantum fluid dynamics and quantum field theory. %stochastic…

Quantum Physics · Physics 2020-04-16 Natália Bebiano , João da Providência , S. Nishiyama , João P. da Providência

Recently, weak measurements have attracted a lot of interest as an experimental method for the investigation of non-classical correlations between observables that cannot be measured jointly. Here, I explain how the complex valued…

Quantum Physics · Physics 2013-05-02 Holger F. Hofmann

Quantum systems usually travel a multitude of different paths when evolving through time from an initial to a final state. In general, the possible paths will depend on the future and past boundary conditions, as well as the system's…

Quantum Physics · Physics 2016-08-30 Aharon Brodutch , Eliahu Cohen

The concept of a \emph{weak value} of a quantum observable was developed in the late 1980s by Aharonov and colleagues to characterize the value of an observable for a quantum system in the time interval between two projective measurements.…

Quantum Physics · Physics 2015-12-17 J. M. Farinholt , A. Ghazarians , J. E. Troupe

We present a mathematical formalism of non-Hermitian quantum mechanics, following the Dirac-von Neumann formalism of quantum mechanics. In this formalism, the state postulate is the same as in the Dirac-von Neumann formalism, but the…

Quantum Physics · Physics 2022-03-29 Zeqian Chen

"Weak measurements" -- involving a weak unitary interaction between a quantum system and a meter followed by a projective measurement -- are investigated when the system has a non-Hermitian Hamiltonian. We show in particular how the…

Quantum Physics · Physics 2012-12-21 A. Matzkin

Examples are given of non-Hermitian Hamiltonian operators which have a real spectrum. Some of the investigated operators are expressed in terms of the generators of the Weil-Heisenberg algebra. It is argued that the existence of an…

Quantum Physics · Physics 2009-09-29 João da Providência , Natália Bebiano , João Pinheiro da Providência
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