Helmholtz-resonator measurements of the superfluid density of liquid<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mmultiscripts><mml:mrow><mml:mi mathvariant="normal">He</mml:mi></mml:mrow><mml:mprescripts /><mml:mrow /><mml:mrow><mml:mn>4</mml:mn></mml:mrow><mml:mrow /><mml:mrow /></mml:mmultiscripts></mml:mrow></mml:math>in submicrometer-diameter channels

Brooks, J. S.; Sabo, B. B.; Schubert, P. C.; Zimmermann, W.

doi:10.1103/physrevb.19.4524

Cited by 43 publications

(10 citation statements)

References 43 publications

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“…The first approach for probing nonlinear currentphase relations was suggested by Zimmermann (Brooks et al, 1979) in the context of vortex phase slippage in 4 He. The method focuses on the dynamical behavior of a single aperture [whose I() one wishes to know] shunted by a larger tube.…”

Section: A Methods Imentioning

confidence: 99%

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Superfluid3HeJosephson weak links

Davis

Packard

2002

Rev. Mod. Phys.

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Josephson weak links between samples of macroscopic quantum systems such as superconductors, superfluids, and Bose-Einstein condensates provide a unique tool with which to explore quantum mechanics and an opportunity to create applications based on macroscopic quantum physics. In this review we describe the development of the field of weak links in superfluid 3 He. We review the basic techniques used to study this system and then describe the experimental and theoretical milestones that have led to our present understanding. CONTENTS

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Section: A Methods Imentioning

confidence: 99%

“…This team studied the shuntedaperture topology but now coupled to a membrane (Brooks et al, 1979). The weak link was nominally a slit of approximate dimensions 0.3ϫ5 m 2 .…”

Section: A Methods Imentioning

confidence: 99%

Superfluid3HeJosephson weak links

Davis

Packard

2002

Rev. Mod. Phys.

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“…(8) is l~ rrpa'Tm. Therefore, the period increase in the case of the 2.8 pm cell according to above assumptions can be written as oP = ~ 8I P = 3646P", (ps), 2 I (9) where Pm is the pressure in Torr. This equation is shown as a dashed line in Fig.…”

Section: Ref-outmentioning

confidence: 99%

Si wafers uniformly spaced; bonding and diagnostics

Rhee

Gasparini

Petrou

et al. 1990

Review of Scientific Instruments

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A new Si-Si0 2 bonding process has been developed to achieve a uniform spacing between two silicon wafers of 2 and 3 in. diam. Spacings between 0.1 and 3.9 11m have been obtained so far. Hydrostatic pressure is used to force the two wafers into intimate contact at points where bonding is desired. The bonding is performed at a temperature of -1150 0c. The uniformity of bonding and spacing between the wafers is checked by a Fabry-Perot interferometer technique at room temperature and by measurements of superfluid density of He II at low temperature. These results are compared with ellipsometer and stylus measurements of the oxide thickness which is designed to govern the wafers' spacing. We find that these different techniques yield consistent results.

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“…17'), using closed-form expressions for the various thermodynamic functions tabulated in the Appendix of Ref. 1…”

Section: Superfluid Densitymentioning

confidence: 99%

Measurements of superfluid densities and critical superfluid mass currents of pure 4He and 3He/4He mixtures in nuclepore near the lambda transition

Schubert

Zimmermann

1981

J Low Temp Phys

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Measurements have been made of the relative superfluid density psp/ p and the critical mass currentIsc for the onset of dissipation in the superfluid flow of pure 4He and 3He/4He mixtures in the circular cylindrical pores of Nuclepore near the h transition, using a double-ended Helmholtz resonator. Pore diameters of O. 03, O. 1, and 0.4 tzm were studied using 3He mole fractions of O. O, ~ 0.2, and 0.4. For each pore diameter dp and mole fraction x our results for psp/ p were • 0 675 fitted relattvely well by the form C(t-to1) " and those for Isc by the form I~co(t-to~) g, where t=-[Tx -T]/Tx. For each combination of dp and x the reduced onset temperatures to1 and toc are in rough agreement with each other but somewhat larger than values found by others for Nuclepore. For the smaller two pore diameters, these onset temperatures are consistent with the unithat near Tx, h p~b~/m4kBT should be a constant versality hypothesis 2 e independent of T and x. Here h is the reduced Planck constant, P~b is the bulk superfluid density, ~ is the coherence length, m4 is the 4He atom mass, kB is Boltzmann ' s constant, and T is the absolute temperature. At each value of x the amplitudes C agree well with the corresponding amplitude for Psb/P, and g equals 1.17 + 0.04 for all cases. Measurements of the velocity of second sound at x = 0. 000, 0.190, 0.401, and 0.450 are also reported.

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Helmholtz-resonator measurements of the superfluid density of liquidHe4in submicrometer-diameter channels

Cited by 43 publications

References 43 publications

Superfluid3HeJosephson weak links

Superfluid3HeJosephson weak links

Si wafers uniformly spaced; bonding and diagnostics

Measurements of superfluid densities and critical superfluid mass currents of pure 4He and 3He/4He mixtures in nuclepore near the lambda transition

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