CMT148
Electron Bubbles in Superfluid 3He-A: Exploring the Quasiparticle-Ion Interaction
- Author(s):
Oleksii Shevtsov and J. A. Sauls
- Address: Department of Physics & Astronomy, Northwestern University, Evanston, IL 60208
- Date: August 4, 2016
- Journal:
J. Low Temp. Phys., Online First, November 2016, pp. 1-14
[DOI]
[Springer]
[arXiv]
- Abstract:
When an electron is forced into liquid 3He it forms an "electron bubble", a heavy ion with
radius, R ≈ 1.5 nm, and mass, M≈ 100m3, where m3 is the mass of a
3He atom. These negative ions
have proven to be powerful local probes of the physical properties of the host quantum fluid, especially
the excitation spectra of the superfluid phases. We recently developed a theory for Bogoliubov
quasiparticles scattering off electron bubbles embedded in a chiral superfluid that provides a detailed
understanding of the spectrum of Weyl Fermions bound to the negative ion, as well as a theory for the
forces on moving electron bubbles in superfluid 3He-A (Shevtsov et al. in arXiv:1606.06240).
This theory is shown to provide quantitative agreement with measurements reported by the RIKEN group
[Ikegami et al., Science 341:59, 2013] for the drag force and anomalous Hall effect of moving electron
bubbles in superfluid 3He-A. In this report, we discuss the sensitivity of the forces on the
moving ion to the effective interaction between normal-state quasiparticles and the ion. We consider
models for the quasiparticle-ion (QP-ion) interaction, including the hard-sphere potential, constrained
random-phase-shifts, and interactions with short-range repulsion and intermediate range attraction. Our
results show that the transverse force responsible for the anomalous Hall effect is particularly sensitive
to the structure of the QP-ion potential, and that strong short-range repulsion, captured by the
hard-sphere potential, provides an accurate model for computing the forces acting on the moving electron
bubble in superfluid 3He-A.
- Comments: 14 pages, 2 figures, presentation at the International Conference on
Quantum Fluids and Solids, Prague, Czech Republic, 2016
- Eprint:
[PDF]
[arXiv]
Return to index