Theory of the Phonon-Roton Spectrum of Liquid 4He
The theory of the excited states of boson fluids, and particularly liquid 4He, has been the subject of attention for nearly fifty years, beginning with Landau’s observation in 1941 that the unusual properties of liquid 4He at temperatures well below the λ point could be understood in terms of a phonon and roton spectrum of excited states.1 Subsequently Landau asserted without proof that the phonons and rotons were part of a single, continuous spectrum as a function of momentum,2 having essentially the same form as is presently widely accepted.
KeywordsExcitation Spectrum Ground State Wave Function Boson System Condensate Fraction Excited State Structure
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- 1.L. D. Landau, Zh. Eksp. Teor. Fiz. 11: 592 (1941)Google Scholar
- L. D. Landau, J. Phys. Moscow 5: 718 (1941).Google Scholar
- 2.L. D. Landau, J. Phys. Moscow 11: 91 (1947).Google Scholar
- 3.N. Bogoliubov, J. Phys. USSR 11:23 (1947); for further references and discussion, see references 4 and 5.Google Scholar
- 5.P. Nozieres and D. Pines, “The Theory of Quantum Liquids, Volume II,” Addison-Wesley, New York (1990).Google Scholar
- 10.C. E. Campbell, in: “Progress in Liquid Physics,” C. A. Croxton, ed., Wiley, New York (1978).Google Scholar
- 11.H. W. Jackson, private communication.Google Scholar
- 13.E. Feenberg, “Theory of Quantum Fluids,” Academic Press, New York (1969).Google Scholar
- 19.L. R. Whitney, Ph. D. Dissertation, University of Minnesota (1981).Google Scholar
- 20.F. Family, Physica 107B: 699 (1981).Google Scholar
- 21.P. Berdahl, Phys. Rev. 10: 2378 (1981).Google Scholar