| Zugriffsnummer | 12840 |
| Dokumenttyp | Zeitschriftenartikel |
| Sprache | Englisch |
| Titel | Effective mass, spin fluctuations, and zero sound in liquid 3He |
| Autor(in); Institution |
Glyde, H. R.; University of Delaware, Department of Physics and Astronomy, Newark, Delaware, USA
Fåk, B.; Département de Recherche Fondamentale sur la Matière Condensée, Commissariat à l'Energie Atomique, SPSMS/MDN, Grenoble, FRANCE
van Dijk, N. H.; Département de Recherche Fondamentale sur la Matière Condensée, Commissariat à l'Energie Atomique, SPSMS/MDN, Grenoble, FRANCE
Godfrin, H.; CNRS, Centre de Recherches sur les Très Basses Températures, Grenoble, FRANCE
Guckelsberger, Kurt; Q.203, Festkörperphysik, PTB-Braunschweig
Scherm, Reinhard; Q.1, Physikalische Grundlagen, PTB-Braunschweig
|
| Quelle/Jahr | Physical Review B: 61 (2000), 2, 1421 - 1432 |
| ISSN | 0163-1829 |
| DOI | |
| Klassifikationscode | PACS: 67.55.-s ; PACS: 05.30.Fk |
| Freie Schlagworte | Liquid Helium ; Quantum fluids ; Elementary excitations |
| Zusammenfassung | We have measured and calculated the density and spin-density dynamic structure factors Sc(Q,ω) and SI(Q,ω) of normal liquid 3He as a function of wave vector Q and temperature T. The static spin susceptibility, χ(T) and specific heat CV(T) are also calculated. These properties all depend upon the effective mass m*(k,ω) of the Fermi quasiparticles making up the liquid. We use a model in which m* peaks near the Fermi surface to m* = 2.8, the Landau theory effective mass, and decreases towards the bare mass m* = 1 for quasiparticles away from the Fermi energy εF. The theory for all the properties may be viewed as a Landau theory with an effective mass m*(εk) = m*(k) that decreases as the quasiparticle energy εk moves away from εF The peaking of m* at εF is widely predicted in Fermi systems and the aim is to test how important this physical feature is in the dynamics of liquid 3He. We find that Sc(Q,ω) and SI(Q,ω) versus Q and T as well as χ(T) are well reproduced by the model for the same m*(k). The CV(T) can be reproduced, but a much lower value of m*(k) at energies εk away from εF is required, m* ≈ 0.5, as found in previous calculations of CV(T). We conclude that the peaking of m* at εF is an important feature to include in calculations of S(Q,ω) and that the quasiparticle model itself is inadequate for CV at higher temperatures. |
