Physics and Astronomy - Quantum Nano Seminar - Jay Lawrence, Dartmouth College

Dartmouth Events

Physics and Astronomy - Quantum Nano Seminar - Jay Lawrence, Dartmouth College

Title: "Observing A Quantum Measurement"

Thursday, February 14, 2019
Wilder 202
Intended Audience(s): Public
Categories: Lectures & Seminars

ABSTRACT: The quantum measurement problem has been stated (review of M. Schlosshauer, 2018) as “the question of how to reconcile the linear, deter- ministic evolution described by the Schr ̈odinger equation with the occurrence of random measurement outcomes,” I will address this question with a varia- tion on the Von Neumann measurement picture as informed by decoherence theory. Envisioning the usual Stern-Gerlach scenario, the variation replaces the canonical “pointer” with an array of quantum two-state systems, one along each path, which can be read out (“observed”) with recording devices (a gedanken experiment which can actually be done). With this arrange- ment, one can choose to “observe” the usual collapse scenario in which the particle chooses one path to the exclusion of the other - or, on the identically prepared state, the superposition of both paths. The model shows why “clas- sical” detectors alone cannot see the superposition. It also clarifies the role of decoherence in “controlled” Von Neumann-type measurements, and shows that the pointer basis of the apparatus is chosen by the observer, not the environment as held by current decoherence theories.

For more information, contact:
Tressena Manning

Events are free and open to the public unless otherwise noted.