Lecture · MIT

The nature of superposition. Mach-Zehnder interferometer

Name: The nature of superposition. Mach-Zehnder interferometer
Duration: 15 min

Zwiebach contrasts classical superposition of fields with the quantum kind using single photons in a Mach-Zehnder interferometer, then states the rule this section builds on: measure a property on αA + βB and you never get anything in between, only a or b, with odds set by |α|² and |β|², after which the state is the one you found. When he says a photon is 'in both beams at the same time', translate it into this section's language (one definite state written as a sum of two path states), and catch his point at about 7:30 that the same vector can be written as a sum in many different ways.

Channel: MIT OpenCourseWare
Institution: MIT · 8.04 Quantum Physics I, Spring 2016
Lecturer: Barton Zwiebach
Runtime: 15 min
Level: Intermediate

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