| Zugriffsnummer | 14022 |
| Dokumenttyp | Zeitschriftenartikel |
| Sprache | Englisch |
| Titel | Theoretical study of the dynamic structure factor of superfluid 4He |
| Autor(in); Institution |
Szwabinski, Janusz; Q.103, Elektronenkorrelation in Vielteilchensystemen, PTB-Braunschweig
Weyrauch, Michael; Q.103, Elektronenkorrelation in Vielteilchensystemen, PTB-Braunschweig
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| Quelle/Jahr | Physical Review B: 64 (2001), 18, 184512-1 - 184512-16 |
| ISSN | 0163-1829 |
| DOI | |
| Klassifikationscode | PACS: 67.40.Db ; PACS: 61.12.-q |
| Zusammenfassung | We study the dynamic structure factor S(q,ω) of superfluid 4He at zero temperature in the roton momentum region and beyond using field-theoretical Green's function techniques. In the Beliaev single particle propagator as well as in the Gavoret-Nozières two-particle propagator we introduce quasiparticle approximations for the one-particle irreducible vertex functions. The resulting Dyson-Schwinger equations are solved self-consistently. We treat the residual (weak) interaction between quasiparticles as being local in coordinate space and weakly energy dependent. Our quasiparticle model explicitly incorporates the Bose-Einstein condensate. A complete formula for the dynamic susceptibility, which is related to S(q,ω), is derived. The structure factor is numerically calculated in a self-consistent way in the special case of a momentum independent interaction between quasiparticles. Results are compared with experiment and other theoretical approaches. |
