Does one still need to "shut up and calculate"?

Abstract

In learning quantum mechanics, an essential question has always been: How does one go about developing a "physical feel" for quantum phenomena? Naturally, one needs a basis or ground zero to start from, and that basis must be unlike anything with which we are already familiar in consequence of our experiences with the world of classical physics. We argue (channeling Richard Feynman) that the most elementary and the least cumbersome concept to build upon is the existence of complex probability amplitudes for physical events. An event that can take place in multiple alternative ways should be treated by adding the corresponding amplitudes when the paths are, in principle, indistinguishable, and by adding the probabilities themselves when the paths are distinguishable. Once we accept this principle and hone our intuition by examining quantum phenomena in its light, we will be on the path to "understanding" quantum mechanics. Elementary examples from the field of quantum optics demonstrate how adherence to Feynman's principle could lead to a better, more "intuitive" appreciation for the magic of quantum mechanics.

15 pages, 5 figures, 46 equations, 18 references

References in corpus (5)

• Fundamental properties of beam-splitters in classical and quantum optics
• Insights into the behavior of certain optical systems gleaned from Feynman's approach to quantum electrodynamics
• Spin-1 photons, spin-1/2 electrons, Bell's inequalities, and Feynman's special perspective on quantum mechanics
• Linear and angular momenta of photons in the context of "which path" experiments of quantum mechanics
• On the quantum theory of light interacting with nano-materials