scholarly journals Energy Spectrum of the Excitations in Liquid Helium II

1969 ◽  
Vol 41 (4) ◽  
pp. 919-940 ◽  
Author(s):  
Sigenobu Sunakawa ◽  
Shuichiro Yamasaki ◽  
Takeji Kebukawa
Keyword(s):  
Energy Spectrum ◽  
Liquid Helium ◽  
Helium Ii

STUDIES OF THE ENERGY SPECTRUM AND THE WAVE FUNCTION FOR LOW ENERGY EXCITED STATES IN LIQUID HELIUM II

2007 ◽  
Vol 21 (21) ◽  
pp. 1383-1390
Author(s):  
DE-HUA LIN ◽  
PING ZOU ◽  
ZHONG-WEI ZHANG ◽  
HONG-LEI WANG ◽  
JUN PAN ◽  
...  
Keyword(s):  
Experimental Data ◽  
Wave Function ◽  
Energy Spectrum ◽  
Liquid Helium ◽  
Excited States ◽  
Low Energy ◽  
Large Wave ◽  
Helium Ii ◽  
Wave Numbers ◽  
Specific Temperature

In this paper, we study the elementary excitations and energy spectrum proposed by L. D. Landau in liquid helium II. On the basis of the energy spectrum for the phonons and rotons, we put forward a uniform expression of energy spectrum in liquid helium II, which is limited in a specific temperature range. By using the wave function for low energy excited states proposed by R. P. Feynman or the modified one proposed by Feynman and Cohen, it can be found that the estimated energy spectrum is quite different from the experimental data, especially for the region with large wave numbers. By proposing an improved form for the wave function, we re-analyze the energy spectrum in liquid helium II, and our results show a better agreement with the experimental data.

Quantum hydrodynamics and the theory of liquid helium

1953 ◽  
Vol 219 (1137) ◽  
pp. 257-270 ◽  
Keyword(s):  
Energy Spectrum ◽  
Liquid Helium ◽  
Fluid Velocity ◽  
Second Sound ◽  
Quantum Hydrodynamics ◽  
Dynamical Equations ◽  
Helium Ii ◽  
Apparent Variation ◽  
Theory Of Fields ◽  
Good Agreement

The Clebsch formula, u = –∇ ϕ – χ ∇ ψ , for the fluid velocity allows the classical hydro-dynamical equations, including vorticity, to be derived from a variational principle, and put into canonical form. The standard quantization procedure of the theory of fields then gives a set of field operators satisfying the commutation relations obtained (starting from different premises) by Landau (1941). The Hamiltonian contains terms corresponding to the excitation of the ‘roton’ states of Landau’s theory, with an energy spectrum (allowing for the atomicity of real liquids by a ‘cut off’ in the Fourier analysis of the field variables) of the form E = ∆ + p 2 /2 μ . The observed variations of specific heat and second-sound velocity in liquid helium II may be interpreted to give values of ∆ in good agreement with the theory, with an apparent variation of μ with p , perhaps attributable to roton-roton and phonon-roton interactions.

Energy spectrum and phase velocity in two- and three-dimensional liquid helium II

Physica B+C ◽  
1980 ◽  
Vol 100 (1) ◽  
pp. 74-80 ◽  
Author(s):  
A. Isihara ◽  
Soon-Tahk Choh ◽  
Woo-Hyung Kang ◽  
Chung-In Um
Keyword(s):  
Energy Spectrum ◽  
Phase Velocity ◽  
Liquid Helium ◽  
Three Dimensional ◽  
Helium Ii

scholarly journals On the Mechano-Caloric Effect in Liquid Helium II

1950 ◽  
Vol 5 (6) ◽  
pp. 1010-1013 ◽  
Author(s):  
S. Nakajima ◽  
M. Shimizu
Keyword(s):  
Liquid Helium ◽  
Helium Ii ◽  
Caloric Effect

Heat Transfer in Liquid Helium II by Internal Convection

1948 ◽  
Vol 74 (9) ◽  
pp. 1148-1156 ◽  
Author(s):  
F. London ◽  
P. R. Zilsel
Keyword(s):  
Heat Transfer ◽  
Liquid Helium ◽  
Helium Ii ◽  
Internal Convection
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