Generating rotons in superfluids

[elad28]

In superfluid HE-4 there is a kind of phonon called a roton. In most websites they specify some of the information on rotons although, they don't attend to the question of how are these rotons are generated?
Can you refer me to an article on this or do you have an answer on this (how they are generated in superfluid)?

 

[DrClaude]

This article on the observation of rotons in BEC might be useful:
https://www.nature.com/articles/s41567-018-0054-7

 

[SpinFlop]

This is covered very nicely in chapter 2.7 of James Annett's book "Superconductivity, Superfluids, and Condensates". Honestly, I recommend you buy the book and read the whole thing. Like all books in the Oxford Masters Series, it is little more than a slip of a book, but presents an immense amount of information in a simple and easily digestible format.

PS to Mods: The link to the pdf of the book is hosted by a university. I would like to assume this means they have permission to provide the book for free, but remove the link if you think it violates PF rules/ethics.

 

[DrClaude]

PS to Mods: The link to the pdf of the book is hosted by a university. I would like to assume this means they have permission to provide the book for free, but remove the link if you think it violates PF rules/ethics.

I do not think that this pdf of the book is legal (it is a scan from a library copy). I have changed the link to point to the publisher's website.