Sounds in Helium-three

sounds - theory

• https://en.wikipedia.org/wiki/Zero_sound

• Zero and First Sound in Normal Fermi Systems
  Shohei Watabe,1 Aiko Osawa,2 and Tetsuro Nikuni

• https://en.wikipedia.org/wiki/Second_sound

• absorption of sound in He3 Lukyanchuk

nice derivations

• 2021 Optical signatures of shear collective modes in strongly interacting Fermi-liquids D. Valentinis

... up to the Fermi surface. As such, it displays rigidity against perturbations. Such rigidity generates Fermi-surface resonances which manifest as longitudinal and transverse collective modes.

sounds - experiment

• 1966 zero sound - experiments $ \frac{Im \omega}{Re \omega} = $ attenuation (Quantum zero sound) dampening by multi-pair excitations for $ \omega > k_b T$.

1996 Quantum zero sound in helium-3

1975 Observation of Transverse Zero Sound in Normal $He^3$ - Pat R. Roach

more lectures

http://www-thphys.physics.ox.ac.uk/people/SteveSimon/QuantumMatterFullSummer2019.pdf
Fermi-liquid theory p. 18(302), and nice picture 310
http://eduardo.physics.illinois.edu/phys561/FL.pdf

https://phas.ubc.ca/~berciu/TEACHING/PHYS502/PROJECTS/FeLi.pdf p.4 (typo corrected as $(1+ \frac{F_1}{3})$ in Eqn. 21?)
Fermi Liquid Theory: Collective Modes also p.4