Resonance absorption of microwaves in He II: Evidence for roton emission

Journal Article · Mon Oct 01 00:00:00 EDT 2007 · Physical Review. B, Condensed Matter and Materials Physics

DOI:https://doi.org/10.1103/PHYSREVB.76.140503· OSTI ID:21052707

Rybalko, A; Rubets, S; Rudavskii, E; Tikhiy, V ^[1]; Tarapov, S; Golovashchenko, R; Derkach, V ^[2]

---

1. B.I.Verkin Institute for Low Temperature Physics and Engineering, NAS of Ukraine, 47, Lenin Avenue, Kharkov, 61103 (Ukraine)
2. Institute of Radiophysics and Electronics, NAS of Ukraine, 12 Proskury Strasse, 61085 Kharkov (Ukraine)

Microwave (MW) absorption in liquid {sup 4}He is investigated in the frequency range of 40-200 GHz at T=1.4-2.5 K. A 'whispering gallery' of waves was generated by a dielectric disk resonator immersed into the liquid. Resonance absorption of MWs was detected at the frequency, which corresponds to the roton minimum of the liquid helium excitation spectrum. The creation of a single roton is possible because of the presence of the resonator wall which absorbs an extra momentum. The resonance frequency is shown to decrease with temperature in an excellent agreement with the temperature dependence of the roton gap obtained previously in the neutron scattering experiment.

• OSTI ID: 21052707
• Journal Information: Physical Review. B, Condensed Matter and Materials Physics, Vol. 76, Issue 14; Other Information: DOI: 10.1103/PhysRevB.76.140503; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1098-0121
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
DIELECTRIC MATERIALS
EMISSION
EXCITATION
GHZ RANGE
HELIUM
HELIUM 4
LIQUIDS
MICROWAVE RADIATION
NEUTRON DIFFRACTION
RESONANCE
RESONANCE ABSORPTION
RESONATORS
ROTONS
SPECTRA
SUPERFLUIDITY
TEMPERATURE DEPENDENCE