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1. Majidy, Shayan-Shawn. Violation of an augmented set of Leggett-Garg inequalities and the implementation of a continuous in time velocity measurement.

Degree: 2019, University of Waterloo

URL: http://hdl.handle.net/10012/14794

Macroscopic realism (MR) is the view that a system may possess definite properties at any time independent of past or future measurements, and may be tested experimentally using the Leggett-Garg inequalities (LGIs). In this work we advance the study of LGIs in two ways using experiments carried out on a nuclear magnetic resonance spectrometer. Firstly, we addresses the fact that the LGIs are only necessary conditions for MR but not sufficient ones. We implement a recently-proposed test of necessary and sufficient conditions for MR which consists of a combination of the original four three-time LGIs augmented with a set of twelve two-time LGIs. We explore different regimes in which the two- and three-time LGIs may each be satisfied or violated. Secondly, we implement a recent proposal for a measurement protocol which determines the temporal correlation functions in an approximately non-invasive manner. It employs a measurement of the velocity of a dichotomic variable Q, continuous in time, from which a possible sign change of Q may be determined in a single measurement of an ancilla coupled to the velocity. This protocol involves a significantly different set of assumptions to the traditional ideal negative measurement protocol and a comparison with the latter is carried out.

Subjects/Keywords: quantum foundations; quantum information; nuclear magnetic resonance; macrorealism

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^{th} Edition):

Majidy, S. (2019). Violation of an augmented set of Leggett-Garg inequalities and the implementation of a continuous in time velocity measurement. (Thesis). University of Waterloo. Retrieved from http://hdl.handle.net/10012/14794

Note: this citation may be lacking information needed for this citation format:

Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^{th} Edition):

Majidy, Shayan-Shawn. “Violation of an augmented set of Leggett-Garg inequalities and the implementation of a continuous in time velocity measurement.” 2019. Thesis, University of Waterloo. Accessed October 27, 2020. http://hdl.handle.net/10012/14794.

Note: this citation may be lacking information needed for this citation format:

Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^{th} Edition):

Majidy, Shayan-Shawn. “Violation of an augmented set of Leggett-Garg inequalities and the implementation of a continuous in time velocity measurement.” 2019. Web. 27 Oct 2020.

Vancouver:

Majidy S. Violation of an augmented set of Leggett-Garg inequalities and the implementation of a continuous in time velocity measurement. [Internet] [Thesis]. University of Waterloo; 2019. [cited 2020 Oct 27]. Available from: http://hdl.handle.net/10012/14794.

Note: this citation may be lacking information needed for this citation format:

Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Majidy S. Violation of an augmented set of Leggett-Garg inequalities and the implementation of a continuous in time velocity measurement. [Thesis]. University of Waterloo; 2019. Available from: http://hdl.handle.net/10012/14794

Not specified: Masters Thesis or Doctoral Dissertation

University of Oxford

2. Knee, George C. Concepts and applications of quantum measurement.

Degree: PhD, 2014, University of Oxford

URL: http://ora.ox.ac.uk/objects/uuid:2838a30b-302c-4fac-9e86-1ca452a88a83 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.604537

In this thesis I discuss the nature of ‘measurement’ in quantum theory. ‘Measurement’ is associated with several different processes: the gradual imprinting of information about one system onto another, which is well understood; the collapse of the wavefunction, which is ill-defined and troublesome; and finally, the means by which inferences about unknown experimental parameters are made. I present a theoretical extension to an experimental proposal from Leggett and Garg, who suggested that the quantum-or-classical reality of a macroscopic system may be probed with successive measurements arrayed in time. The extension allows for a finite level of imperfection in the protocol, and makes use of Leggett’s ‘null result’ measurement scheme. I present the results of an experiment conducted in Oxford that, up to certain loopholes, defies a non-quantum interpretation of the dynamics of phosphorous nuclei embedded in silicon. I also present the theory of statistical parameter estimation, and discover that a recent trend to employ time symmetric ‘postselected’ measurements offers no true advantage over standard methods. The technique, known as weak-value amplification, combines a weak transfer of quantum information from system to meter with conditional data rejection, to surprising effect. The Fisher information is a powerful tool for evaluating the performance of any parameter estimation model, and it reveals the technique to be worse than ordinary, preselected only measurements. That this is true despite the presence of noise (including magnetic field fluctuations causing deco- herence, poor resolution detection, and random displacements), casts serious doubt on the utility of the method.

Subjects/Keywords: 530.12; Quantum theory (mathematics); Philosophy of physics; Quantum information processing; Theoretical physics; Condensed matter theory; Atomic and laser physics; Africa; Leggett-Garg; Macrorealism; Weak value; Quantum theory; measurement; quantum measurement; weak measurement; null result measurement; venality; Fisher information; parameter estimation; amplification

Record Details Similar Records

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^{th} Edition):

Knee, G. C. (2014). Concepts and applications of quantum measurement. (Doctoral Dissertation). University of Oxford. Retrieved from http://ora.ox.ac.uk/objects/uuid:2838a30b-302c-4fac-9e86-1ca452a88a83 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.604537

Chicago Manual of Style (16^{th} Edition):

Knee, George C. “Concepts and applications of quantum measurement.” 2014. Doctoral Dissertation, University of Oxford. Accessed October 27, 2020. http://ora.ox.ac.uk/objects/uuid:2838a30b-302c-4fac-9e86-1ca452a88a83 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.604537.

MLA Handbook (7^{th} Edition):

Knee, George C. “Concepts and applications of quantum measurement.” 2014. Web. 27 Oct 2020.

Vancouver:

Knee GC. Concepts and applications of quantum measurement. [Internet] [Doctoral dissertation]. University of Oxford; 2014. [cited 2020 Oct 27]. Available from: http://ora.ox.ac.uk/objects/uuid:2838a30b-302c-4fac-9e86-1ca452a88a83 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.604537.

Council of Science Editors:

Knee GC. Concepts and applications of quantum measurement. [Doctoral Dissertation]. University of Oxford; 2014. Available from: http://ora.ox.ac.uk/objects/uuid:2838a30b-302c-4fac-9e86-1ca452a88a83 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.604537