Observation of Stable Superfluid Circulation in Liquid-Helium II at the Level of One, Two, and Three Quantum Units

Whitmore, S.C.; Zimmermann, W.

doi:10.1103/physrevlett.15.389

Cited by 41 publications

(15 citation statements)

References 5 publications

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“…So, in4 He the formation of the SF single particle (with k = 0 and circulation quantum h/m 4 ) and pair (with k = 0 and circulation quantum h/2m 4 ) condensate are quite possible in the temperature range 0 ≤ T ≤ T * B and T * B < T < T λ , respectively. The first signs of these phenomena have been observed only in Ref 165. (see alsoRef.…”

mentioning

confidence: 89%

The Microscopic Theory of Superfluidity and Superconductivity Driven by Single Particle and Pair Condensation of Attracting Bosons

Dzhumanov

1998

Int. J. Mod. Phys. B

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A original microscopic theory of superfluidity and superconductivity driven by the single particle (SPC) and pair condensation (PC) of attracting bosons both in Fermi and in Bose systems is developed. This theory (as distinct from the existing theories) for Fermi systems contains two order parameters ∆ F and ∆ B characterizing the attracting fermion pairs and boson pairs, respectively. In such systems superconducting (SC) phase transition is accompanied, as a rule, by the formation of k-space composite bosons (e.g. Cooper pairs and bipolarons) with their subsequent transition to the superfluid (SF) state by attractive SPC and PC. A novel Fermi-liquid and SF Bose-liquid theories are elaborated for description this two-stage Fermi-Bose-liquid (FBL) scenario of SC (or SF) transition. The crossover from k-to real (r)-space pairing regime for BCS-like coupling constants γ F 0.7 − 0.9 and the irrelevance of r-space pairs to the superconductivity are shown. The developed SF Bose-liquid theory predicts the first-order phase transition SPC ↔ PC of attracting 3d-bosons with the kink-like behaviors of all SC (SF) parameters near T = T * B < Tc in accordance with the observations in 4 He, 3 He and superconductors. It is argued that the coexistence of the order parameters ∆ F and ∆ B leads to the superconductivity by two FBL scenarios. One of these scenarios is realized in the so-called fermion (type I, II and III) superconductors (FSC) (where formation of k-space composite bosons and their condensation occur at the same temperature) and the other in the boson (type II and III) superconductors (BSC) (where BCS-like pairing take place in the normal state with manifesting of the second-order phase transition and opening of the pseudogap at T = T F > Tc). There the gapless superfluidity (superconductivity) is caused by the gapless excitation spectrum of bosons at T ≤ T * B and not by the presence of point or line nodes of the BCS-like gap ∆ F assumed in some s-, pand d-pairing models. The 3D-and 2D-insulator-metal-superconductor phase diagrams are presented. The necessary and sufficient microscopic criterions for superfluidity is formulated. The theory proposed are in close agreement with the observations in 4 He, 3 He, superconductors, nuclear and neutron star matter, cosmology, etc.

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mentioning

confidence: 89%

The Microscopic Theory of Superfluidity and Superconductivity Driven by Single Particle and Pair Condensation of Attracting Bosons

Dzhumanov

1998

Int. J. Mod. Phys. B

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“…Minimizing F with respect to R, 3F f mr ■ "• (12) we get R = 19.3 A. This model predicts that the radius of the negative ion will decrease as the external pressure is increased.…”

mentioning

confidence: 81%

Ion trapping in rotating superfluid liquid helium under pressure

Pratt¹

1967

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“…7, the slope of the line indicates a Debye-Waller factor ^2=0.25 A in excellent agreement with a value 0.28 A obtained from observations at K<VJ A" 1 . This is easily understandable, as the Schofield model 5 6 7. Intensity of the quasi-elastic peak (for pentane at 293°K) plotted as a function of K 2 , showing that even for K values >v5 A" 1 a Debye-Waller factor for the internal proton motions governs this peak intensity.…”

Section: A K 2 >3a~2mentioning

confidence: 94%

“…(3a) and (3b) may be approximated by (2h/T 0 )(il 2 +DTo), so that P= ("Z> ,, -Z>)2To=2Too(l+ro/To')( a Z) ,, -^). (5) Using this formula, I 2 is calculated for each temperature using our measured values TOO, TO, T 0 ', and "D" combined with Partington's values for D. The result is seen in the last column of Table I. It is clear that I 2 comes out as a constant, independent of temperature within about 5%.…”

Section: A N-propyl Alcoholmentioning

confidence: 95%

“…If the beryllium-filled cold-neutron spectrum is used for the investigation, the intensity is determined by the intensity at half-maximum multiplied by the width value uncorrected for resolution. 5 If the ingoing spectrum is shaped by a crystal spectrometer, the full area of the separated quasi-elastic peak defines the intensity to use in the determination of u t 2 +u r 2 .…”

Section: Wave Length Amentioning

confidence: 99%

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Proton Motions in Complex Hydrogenous Liquids. II. Results Gained from Some Neutron-Scattering Experiments

et al. 1966

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In an accompanying paper, a cross section for the quasi-elastically scattered neutron spectra from certain types of hydrogenous liquids is given. In the present paper a comparison is made between this theoretical model and some neutron-scattering results obtained on w-propyl alcohol and pentane. The quasi-elastically scattered neutron intensity is analyzed in terms of the relaxation times TO, TI, TO', and TI', the jump length / of the proton, and the self-diffusion coefficient D of the molecular center of gravity. The nature of the quasielastically scattered neutron intensity is generally interpreted as a result of mixed protonic jumps and molecular diffusion. It is shown that the diffusion coefficients derived from neutron-scattering data consist of a combination Z)-j-/ 2 /2ro, where for very low viscosities D dominates and for higher viscosities the protonic diffusion constant 1 2 /2TQ dominates. Protonic jump lengths of 1.5 A are observed. Definite values of the relaxation times TOO, TO', and TO are derived from the width of the quasi-elastic line. With the present resolution of the experimental equipment, times TOO in the range lQr n to 2X10~U sec may be studied. It is shown how in the low-temperature, high-viscosity ranges, r

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Observation of Stable Superfluid Circulation in Liquid-Helium II at the Level of One, Two, and Three Quantum Units

Cited by 41 publications

References 5 publications

The Microscopic Theory of Superfluidity and Superconductivity Driven by Single Particle and Pair Condensation of Attracting Bosons

The Microscopic Theory of Superfluidity and Superconductivity Driven by Single Particle and Pair Condensation of Attracting Bosons

Ion trapping in rotating superfluid liquid helium under pressure

Proton Motions in Complex Hydrogenous Liquids. II. Results Gained from Some Neutron-Scattering Experiments

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