DocumentCode :
3667160
Title :
Correlations of weak quantum measurements in a non-Markovian detection scheme
Author :
Johannes Buelte;Adam Bednorz;Wolfgang Belzig
Author_Institution :
Fachbereich Physik, Universitä
fYear :
2015
fDate :
6/1/2015 12:00:00 AM
Firstpage :
1
Lastpage :
4
Abstract :
Generalized quantum measurement schemes are described by positive operator-valued measures going beyond the projection postulate, which predicts the instantaneous collapse of the systems wave function. This allows to take the noninvasive limit and investigate the correlations of such weak measurements which facilitate the observation of non-commuting observables within the same system. We propose a scheme in which the detector is coupled to the measured system for a finite time, as it is the case in many real setups. This leads to non-Markovian effects appearing by memory functions which are related to symmetric and antisymmetric correlators of the detector variables. We investigate these functions addressing the role of equilibrium and non-equilibrium detectors and how they differ from and could realize the standard Markovian measurement respectively. The latter scheme leads to the symmetrized operator order (aka Keldysh ordering), which is widely used in quantum measurement discussions. We show that the non-Markovian measurement scheme yields information beyond the standard approach, allowing e.g. for the prove of the non classical nature of a system (quasiprobability statistics) by second-order correlation functions.
Keywords :
"Detectors","Correlation","Temperature measurement","Noise","Noise measurement","Current measurement","Fluctuations"
Publisher :
ieee
Conference_Titel :
Noise and Fluctuations (ICNF), 2015 International Conference on
Type :
conf
DOI :
10.1109/ICNF.2015.7288572
Filename :
7288572
Link To Document :
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