2003/04/30 by Nobuhiko Yokoshi, Susumu Kurihara · 1 citation
Physics and Astronomy · #Atomic and Subatomic Physics Research #Cold Atom Physics and Bose-Einstein Condensates #Quantum, superfluid, helium dynamics #cond-mat.soft #cond-mat.stat-mech
paper · pdf · doi:10.1103/physrevb.68.064501
published as Phys. Rev. B 68 064501 (2003) · 5 page, 3 figures
openalex publication_date 2003/08/04 · arxiv created 2005/04/18 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We investigate the collective excitations of 3He--4He mixture films at zero temperature within the random phase approximation and linear response theory. In a low concentration regime of 3He, a level repulsion between zero sound and third sound modes is derived, which opens the possibility to observe quantum mechanical coherence between a 3He particle-hole pair and the condensate of 4He. We also investigate the 3He--4He vertex corrections in the ladder approximation, and show that the third branch, the combined mode of fermionic particle-hole pair and the third sound quanta, provides a unique correction to the Landau f function. Some implications for a fermion-boson mixture of alkali atoms in a potential trap are discussed.