Third sound, two-dimensional hydrodynamics, and elementary excitations in very thin helium films

1978 ◽  
Vol 18 (5) ◽  
pp. 2155-2168 ◽  
Author(s):  
J. E. Rutledge ◽  
W. L. McMillan ◽  
J. M. Mochel ◽  
T. E. Washburn
Keyword(s):  
Two Dimensional ◽  
Helium Films ◽  
Elementary Excitations ◽  
Third Sound ◽  
Thin Helium Films

scholarly journals Cyclotron resonance for two-dimensional electrons on thin helium films

2002 ◽  
Vol 65 (16) ◽  
Author(s):  
J. Klier ◽  
A. Würl ◽  
P. Leiderer ◽  
G. Mistura ◽  
V. Shikin
Keyword(s):  
Cyclotron Resonance ◽  
Two Dimensional ◽  
Helium Films ◽  
Thin Helium Films

TWO DIMENSIONAL LARGE AMPLITUDE QUASI SOLITONS IN THIN HELIUM FILMS

1990 ◽  
Vol 04 (01) ◽  
pp. 47-51 ◽  
Author(s):  
J. SREEKUMAR ◽  
V. M. NANDAKUMARAN
Keyword(s):  
Large Amplitude ◽  
Local Density ◽  
Van Der Waals ◽  
Density Fluctuations ◽  
Two Dimensional ◽  
Helium Films ◽  
Amplitude Fluctuations ◽  
Thin Helium Films ◽  
Full Nonlinearity

Large amplitude local density fluctuations in a thin superfluid 4 He film is considered. It is shown that these large amplitude fluctuations travel and behave like "quasi-solitons" under collision, even when the full nonlinearity arising from the Van der Waals potential is taken into account.

Third sound and the superfluid parameters of thin helium films

1970 ◽  
Vol 3 (3) ◽  
pp. 225-234 ◽  
Author(s):  
I. Rudnick ◽  
J. C. Fraser
Keyword(s):  
Helium Films ◽  
Third Sound ◽  
Thin Helium Films

Excitations in Few-Atomic-Layer Adsorbed Helium Films: The Two-Dimensional Roton

1980 ◽  
Vol 44 (4) ◽  
pp. 266-269 ◽  
Author(s):  
W. Thomlinson ◽  
J. A. Tarvin ◽  
L. Passell
Keyword(s):  
Atomic Layer ◽  
Two Dimensional ◽  
Helium Films

Variable transfer rates in superfluid helium films

1966 ◽  
Vol 290 (1420) ◽  
pp. 1-13 ◽  
Keyword(s):  
Thick Film ◽  
Superfluid Helium ◽  
Transfer Rate ◽  
Bath Surface ◽  
Helium Films ◽  
Third Sound ◽  
Transfer Rates ◽  
Superfluid Flow ◽  
Helium Bath ◽  
The Difference

From an experimental investigation of superfluid film transfer in narrow beakers in helium II it emerges that there are probably two kinds of film. A ‘normal’ film is formed by superfluid creep over a dry substrate. A ‘thick’ film remains when liquid has drained from a substrate that has previously been immersed in the liquid helium bath. A comparison has been made of the superfluid flow between the two types of film. Scatter of values of transfer rate associated with a normal film is attributed to third sound generated by bath waves impinging on the meniscus at the base of the film. The thick film shows an enhanced rate of transfer which can persist for long periods of time in quiet conditions, but which can be abruptly diminished by disturbances such as bath surface agitation. There is a maximum stable length for a thick film exhibiting the full enhanced rate. The enhanced rate can be as much as 60% greater than the normal rate at 1° K, but the difference between the two rates of transfer disappears above 1.8 °K. No enhanced rate of transfer at any temperature is observed in beakers as large as 8 mm diameter.

Comments on the article: ‘The two-fluid model of the helium film’

1973 ◽  
Vol 333 (1593) ◽  
pp. 261-263 ◽  
Keyword(s):  
Superfluid Helium ◽  
Fluid Model ◽  
Convection Velocity ◽  
Thermodynamic Approach ◽  
Helium Film ◽  
Helium Films ◽  
Third Sound ◽  
Superfluid Flow ◽  
Two Fluid Model ◽  
Two Fluid

It is argued that the thermodynamic approach used by Goodstein and Saffman in their theory of thin superfluid helium films is incorrect. Their theory does not explain Keller’s experiment. The value they obtained for the convection velocity of third sound in a film with superfluid flow is consequently unfounded theoretically. Their calculation of third sound attenuation is shown to be incomplete.

scholarly journals Ultrafast two-dimensional terahertz spectroscopy of elementary excitations in solids

2013 ◽  
Vol 15 (2) ◽  
pp. 025039 ◽  
Author(s):  
Michael Woerner ◽  
Wilhelm Kuehn ◽  
Pamela Bowlan ◽  
Klaus Reimann ◽  
Thomas Elsaesser
Keyword(s):  
Terahertz Spectroscopy ◽  
Two Dimensional ◽  
Elementary Excitations
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