Frictional relaxation time of 3He normal fluid component in aerogel obtained by fourth sound resonance

C. Kato, T. Matsukura, Y. Nago, K. Obara, H. Yano, O. Ishikawa, T. Hata, S. Higashitani, K. Nagai

Research output: Contribution to journalArticle

Abstract

Recently, we revealed that the motion of the normal fluid component in the aerogel is well described by the frictional relaxation model (Higashitani et al. in Phys. Rev. B 71:134508, 2005). To clarify the origin of the friction between the quasiparitcles and the aerogel, we have performed the fourth sound resonance experiments at two different pressures. The fourth sound resonance experiment can derive both the static and the dynamic informations simultaneously, namely, the superfluid fraction and the energy loss. From the static part, we found that the superfluid fraction slightly changes with changing the pressure. We calculated the density of states in the impurity system by means of HSM and propose that the constituent of the normal fluid component is the quasiparticles at emerging levels in the energy gap, which we call the midgap states. From the dynamic part, we found that the energy loss depends on the pressure, in contrast to the superfluid fraction. The pressure dependence of the frictional relaxation time has been calculated, and we revealed that the response of the normal fluid component against the frictional force depends on the BCS coherence length.

Original languageEnglish
Pages (from-to)182-187
Number of pages6
JournalJournal of Low Temperature Physics
Volume158
Issue number1-2
DOIs
Publication statusPublished - 2010 Jan 1

    Fingerprint

Keywords

  • Aerogel
  • Hydrodynamics
  • Restricted geometry
  • Superfluid herium-3

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics
  • Materials Science(all)
  • Condensed Matter Physics

Cite this

Kato, C., Matsukura, T., Nago, Y., Obara, K., Yano, H., Ishikawa, O., Hata, T., Higashitani, S., & Nagai, K. (2010). Frictional relaxation time of 3He normal fluid component in aerogel obtained by fourth sound resonance. Journal of Low Temperature Physics, 158(1-2), 182-187. https://doi.org/10.1007/s10909-009-0003-z