I’ve been puzzling over this paper, “Including nuclear degrees of freedom in a lattice Hamiltonian” by Peter Hagelstein and Irfan Chaudhary. I think I’ve made progress in understanding it. I’ll summarize what I think is going on. But I could be totally wrong 😛
As I explained in the last post, about superradiance, we are gearing up to discuss Peter Hagelstein’s spin-boson model” theory of cold fusion. The theory relies very heavily on two effects that make it easier to transfer energy to an oscillation mode: Dicke superradiance and stimulated emission. This post goes over how stimulated emission works in quantum mechanics. It’s much simpler than the last post, don’t worry. As before, experts can skip this post.
Superradiance was first described by Dicke in 1954 in this paper (official link). If you are a laser / optical physics expert, then you already know all about it. For everyone else, this post is an introductory tutorial.
Motivation: What does superradiance have to do with cold fusion? Well, I’m gearing up to discuss Peter Hagelstein’s “spin-boson model” theory of cold fusion. This theory says that the 24MeV of energy from D+D→⁴He fusion goes more-or-less directly into exciting a billion or so phonons (all of them in a single phonon mode, i.e. all at the same frequency, wavelength, etc.). Normally, this process would be extremely unlikely. However, there are two famous effects that increase the probability of transferring energy to an oscillation mode: Dicke superradiance and stimulated emission. Accordingly, the spin-boson model relies very heavily on both of these principles.
Since it’s impossible to thoroughly understand the spin-boson model without understanding superradiance, and since I couldn’t find a suitable description online, I wrote out this post. Buckle your seatbelts, let’s do some physics!