Corpus ID: 235293929

# Negative group velocity and Kelvin-like wake in superfluid $^{4}He$

@inproceedings{Kolomeisky2021NegativeGV,
title={Negative group velocity and Kelvin-like wake in superfluid \$^\{4\}He\$},
author={E. B. Kolomeisky and Jonathan Colen and J. Straley},
year={2021}
}
• Published 2021
• Physics
The dispersion law Ω(k) of elementary excitations in superfluid He is a non-monotonic function of the wave number k. After an initial increase, the function Ω(k) reaches a maximum followed by a ”roton” minimum at finite k. As a result, there is a range of k between these extrema where the elementary excitations have negative group velocity. These excitations are generated when a fast heavy impurity travels through the superfluid or the latter flows past an obstacle with the speed exceeding 60 m… Expand

#### References

SHOWING 1-10 OF 15 REFERENCES
Density pattern in supercritical flow of liquid He-4
• Physics
• 2005
A density-functional theory is used to investigate the instability arising in superfluid $^{4}\mathrm{He}$ as it flows at velocity $u$ just above the Landau critical velocity of rotons ${v}_{c}$.Expand
Kelvin-Mach Wake in a Two-Dimensional Fermi Sea.
• Physics, Medicine
• Physical review letters
• 2018
The dispersion law for plasma oscillations in a two-dimensional electron gas in the hydrodynamic approximation interpolates between Ω∝sqrt[q] and Ω∝q dependences as the wave vector q increases. As aExpand
Model of superflow with rotons.
• Physics, Medicine
• Physical review letters
• 1993
The Gross-Pitaevskii equation for neutral superflows is extended to a model with a roton minimum in the dispersion curve and an analytical approach to the problem is sketched in the weak amplitude limit. Expand
Macroscopic quantum tunneling of vortices in He II.
• Physics, Medicine
• Physical review letters
• 1988
Experimental evidence is presented showing that the creation of vortices in He II involves macroscopic quantum tunneling through, or thermal activation over, a potential-energy barrier E, in excellent agreement with the theoretical value predicted by Muirhead, Vinen, and Donnelly. Expand
Kelvin–Froude wake patterns of a traveling pressure disturbance
• Geology, Physics
• 2021
Abstract According to Kelvin, a point pressure source uniformly traveling over the surface of deep calm water leaves behind universal wake pattern confined within 39 ° sector and consisting of theExpand
Vortex nucleation in isotopically pure superfluid 4He.
• Physics
• 1980
The first experimental measurements of the rate nu at which vortex rings are nucleated by negative ions in isotopically pure superfiuid 4He are presented. It is found that nu is considerably smallerExpand
Roton creation and vortex nucleation in superfluids
• Physics
• 2000
Abstract The nonlocal nonlinear Schrodinger equation is used to analyze the superfluid flow around an impurity. The differences between the processes of vortex nucleation and roton creation areExpand
On ship waves
• Mathematics
• 1993
Abstract In the first part of the paper asymptotic representations at infinity of the Green function, of the velocity potential and of the elevation of the free surface are obtained for the linearExpand
Statistical Physics
Statistical Physics. By F. Mandl. Pp. xiii + 379. (Wiley: London and New York, July 1971.) £2.75. Statistical Physics. By A. Isihara. Pp. xv + 439. (Academic: New York and London, June 1971.) \$18.50;Expand