Excitations in superfluid 4He and the condensate

Reatto, L.; Masserini, G. L.; Vitiello, S. A.

doi:10.1016/0921-4526(94)90213-5

Cited by 11 publications

(15 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Several methods of determination of the wave function (WF) Ψ 0 of the ground state (GS) of helium-II are available [8][9][10][11][12][13][14][15][16][17][18][19][20] (see also reviews [21][22][23]). In order not to take the boundaries into account, they used periodic boundary conditions (BCs) with passing to the T-limit.…”

Section: Ground State Of He Ii: Equationsmentioning

confidence: 99%

See 1 more Smart Citation

Microstructure of He II in the Presence of Boundaries

Tomchenko

2014

Ukr. J. Phys.

View full text Add to dashboard Cite

We have studied the microstructure of a system of interacting Bose particles under zero boundary conditions and have found two possible orderings. One ordering is traditional and is char-The second one is new and is characterized by the same dispersion law, but with q = 2 −d , where d is the number of noncyclic coordinates. At a weak interaction, the groundstate energy is less for the new solution. The boundaries affect the bulk microstructure due to the difference of the topologies of closed and open systems. K e y w o r d s: Bose particles, Bogolyubov dispersion law, Bose liquid, Bose gas.

show abstract

Section: Ground State Of He Ii: Equationsmentioning

confidence: 99%

“…However, the structure of (62) is the assumption, though no solution with another structure was found. The solution for ψ k with "shadow" variables [17,18] is equivalent to (62), (63).…”

Section: Excited State Of He IImentioning

confidence: 99%

Microstructure of He II in the Presence of Boundaries

Tomchenko

2014

Ukr. J. Phys.

View full text Add to dashboard Cite

show abstract

“…1-3͒ has shown to be a powerful tool in the investigation of quantum solids and liquids obeying Bose statistics. In the context of variational Monte Carlo ͑VMC͒ calculations, it has allowed for studying many properties of superfluid and solid 4 He: the crystallization, 3,4,10 the excitation spectrum both at zero 5 and at finite temperature, 6,7 the properties of the roton at finite temperature, 8 and the liquid-solid coexistence. 9 In this work we apply the shadow wave function ideas to the ground state of a Fermi system.…”

Section: Introductionmentioning

confidence: 99%

Shadow wave function for liquid and solidHe3

et al. 1996

Self Cite

View full text Add to dashboard Cite

The ideas of the shadow wave function are applied to construct a variational wave function to describe the liquid and the solid phase of a system that obeys Fermi statistics. The shadow variables are introduced in the symmetric correlating factor. The antisymmetric part is a standard determinant of plane waves modified by backflow effect. Variational Monte Carlo calculations for 3 He provide ground-state energies in the liquid phase at the level of the most elaborate trial function available in the literature. With this wave function, properties like translational invariance and antisymmetry under particle interchange are maintained even in the crystalline phase.

show abstract

“…We assume that the λ-transition in the bulk He-II is accompanied by complete exhaustion of the one-particle condensate. According to the calculation [27], the fraction of the one-particle condensate is n 0 = 0.078 at T = 0, and n 0 = 0.058 at T = T λ = 2.17 K, i.e., the condensate does not vanish completely at T = T λ , although n 0 (T λ ) ≈ 0 in the experiment. It is suggested in [27] that the one-particle condensate in He-II is exhausted completely [n 0 (T λ ) = 0] because of vortex rings.…”

Section: On the Possibility Of A Jump In The Curve T M (D)mentioning

confidence: 94%

“…According to the calculation [27], the fraction of the one-particle condensate is n 0 = 0.078 at T = 0, and n 0 = 0.058 at T = T λ = 2.17 K, i.e., the condensate does not vanish completely at T = T λ , although n 0 (T λ ) ≈ 0 in the experiment. It is suggested in [27] that the one-particle condensate in He-II is exhausted completely [n 0 (T λ ) = 0] because of vortex rings. The rings were not taken into account in the calculation of [27], and the decrease in n 0 at T → T λ was due to rotons: the number of the atoms pulled out of the condensate was directly proportional to the number of rotons.…”

Section: On the Possibility Of A Jump In The Curve T M (D)mentioning

confidence: 94%

Possible Experiment for Determination of the Role of Microscopic Vortex Rings in the λ-transition in He-II

Tomchenko

2005

J Low Temp Phys

View full text Add to dashboard Cite

It is suggested that microscopic vortex rings (MVR) play an important role in the λ-transition in helium-II and substantially determine the value of T λ . For very thin films of He-II, with thickness d less than the size of the smallest MVR, the rings do not fit in and, therefore, do not exist in such films. Consequently, for superfluid films of He-II, a peculiarity in the form of a smoothed-out jump should be observed in the curve T m (d) at the values of thickness approximately equal to the size of the smallest MVR, d ≈ 6Å ± 3Å (T m is the temperature of the maximum of the broad peak on the curve of the dependence of the specific heat on temperature). The absence of a similar peculiarity will be an evidence that MVR do not influence the values of T λ and T m , and do not play any key role in the λ-transition. The currently available experimental data are insufficient for revealing the predicted peculiarity.

show abstract

Excitations in superfluid 4He and the condensate

Cited by 11 publications

References 27 publications

Microstructure of He II in the Presence of Boundaries

Microstructure of He II in the Presence of Boundaries

Shadow wave function for liquid and solidHe3

Possible Experiment for Determination of the Role of Microscopic Vortex Rings in the λ-transition in He-II

Contact Info

Product

Resources

About