Quantum

"Measurement of the second kind"

Measurement of the second kind — with irreversible detection[edit]
Discussions of measurements of the second kind can be found in most treatments on the foundations of quantum mechanics, for instance, ; ; and .

J. M. Jauch (1968). Foundations of Quantum Mechanics. Addison-Wesley. p. 165

B. d'Espagnat (1976).Conceptual Foundations of Quantum Mechanics. W. A. Benjamin. pp. 18, 159

W. M. de Muynck (2002). Foundations of Quantum Mechanics: An Empiricist Approach. Kluwer Academic Publishers. section 3.2.4

In a measurement of the second kind the unitary evolution during the interaction of object and measuring instrument is supposed to be given by ... in which the states  of the object are determined by specific properties of the interaction between object and measuring instrument. They are normalized but not necessarily mutually orthogonal. The relation with wave function collapse is analogous to that obtained for measurements of the first kind, the final state of the object now being  with probability  Note that many measurement procedures are measurements of the second kind, some even functioning correctly only as a consequence of being of the second kind. For instance, a photon counter, detecting a photon by absorbing and hence annihilating it, thus ideally leaving the electromagnetic field in the vacuum state rather than in the state corresponding to the number of detected photons; also the Stern–Gerlach experiment would not function at all if it really were a measurement of the first kind.[5]

Mott problem

Quantum eraser

EPR-steering

Tomography measurement

Homodyne tomography

Single particle entanglement

Renninger experiment, Interaction-free measurement

Afshar experiment

Decoherence Wigner function
 * "Experiment and the foundations of quantum physics" - Anton Zeilinger vs 
 * "Wave-particle dualism and complementarity unraveled by a different mode" Ralf Menzela,1,Dirk Puhlmanna,Axel Heuera, and Wolfgang P. Schleichb

CHSH inequality

Leggett inequality

Leggett–Garg inequality

It is now generally accepted that the description of quantum mechanics in which all self-adjoint operators represent observables is untenable.[14][15] For this reason, observables are identified with elements of an abstract C*-algebraA (that is one without a distinguished representation as an algebra of operators) and states are positive linear functionals on A. However, by using the GNS construction, we can recover Hilbert spaces which realize A as a subalgebra of operators.

Wheeler's delayed choice experiment

Weak measurement

Continuous measurement

Hardy paradox -- http://en.wikipedia.org/wiki/Hardy%27s_paradox

Englert–Greenberger duality relation

Fresnel–Arago laws

Quantum Eraser + Superluminal issue

QFT Learning