1 / 36

Measurements of the Leggett Frequency in 3 He-B in Aerogel

Measurements of the Leggett Frequency in 3 He-B in Aerogel. V.V.Dmitriev , V.V. Zavjalov, D.Ye. Zmeev, N.Mulders +. Kapitza Institute, Moscow. University of Delaware, USA. solid 3 He. «A». «B». P (bar). normal phase. T (mK). Conditions of our experiments:. bar. Oe. kHz. w-w L. 0.

robert-price
Download Presentation

Measurements of the Leggett Frequency in 3 He-B in Aerogel

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Measurements of the Leggett Frequency in3He-B in Aerogel V.V.Dmitriev, V.V. Zavjalov, D.Ye. Zmeev, N.Mulders+ Kapitza Institute, Moscow University of Delaware, USA

  2. solid 3He «A» «B» P (bar) normal phase T (mK) Conditions of our experiments: bar Oe kHz

  3. w-wL 0 b q0 “Usual” bulk 3He-B: Brinkman-Smith mode: w =

  4. Dwmax 0 Low excitation CW NMR in 3He-B: the form of the line is defined by distribution of vector n n

  5. Dwmax 0 Low excitation CW NMR in 3He-B: the form of the line is defined by distribution of vector

  6. Experimental chamber No 1 1 см

  7. Low excitation CW NMR lines in 3He-B in aerogel in different cells for the same conditions

  8. w-wL 0 b q0 “Usual” bulk 3He-B: Brinkman-Smith mode: w =

  9. Initial frequency of the FIDS versus the tipping angle b (degrees)

  10. z The HPD in nonlinear CW NMR z1 zw z2 H0 z2 z1

  11. 0.01 Oe 0.005 Oe 0.002 Oe Signal amplitude Oe z (mm) The HPD in nonlinear CW NMR

  12. H h y x M Spatially homogeneous modes of oscillations of the HPD Rotating frame:

  13. Experimental cell for studies of low frequency HPD oscillations

  14. HPD formation in cell with aerogel Absorption & dispersion 0 H-H0 (Oe) H0=284 Oe, С H=0.2 Oe/cm

  15. H h y x M Spatially homogeneous modes of oscillations of the HPD Rotating frame:

  16. Bulk 3He-B Lock-in output time (ms)

  17. Oscillations frequency vs RF-field amplitude Bulk 3He-B. (W/2p)2 (Hz2) h (mOe)

  18. B-like phase of 3He in aerogel Lock-in output time (ms)

  19. Leggett frequency in bulk 3He-B ( ) and in 3He-B in aerogel ( ) (solid line from: P.J.Hakonen et.al., JLTP, 76, 225 (1989)) WB/2p (kHz) T/Tc, T/Tca

  20. Leggett frequency in 3He in aerogel ( ) for 25.5 bars (solid line is for bulk 3He-B : P.J.Hakonen et.al., JLTP, 76, 225 (1989)) WB/2p (kHz) T/Tc, T/Tca

  21. Leggett frequency in 3He in aerogel ( ) for 25.5 bars (solid line is for bulk 3He-B : P.J.Hakonen et.al., JLTP, 76, 225 (1989)) WB/2p (kHz) T/Tc, T/Tca

  22. absorption (arb. units)

  23. Conclusions: - New mode of the HPD oscillations has been found. It has allowed to measure the Leggett frequency in 3He-B in aerogel - Orienting influence of the boundary “aerogel - bulk 3He” on the texture of and n is different from that known for the the boundary “bulk 3He - wall”

  24. Conclusions: - New mode of the HPD oscillations has been found. It has allowed to measure the Leggett frequency in 3He-B in aerogel - Orienting influence of the boundary “aerogel - bulk 3He” on the texture of and n is different from that known for the the boundary “bulk 3He - wall” is parallel to the boundary “aerogel-bulk 3He”?

  25. Absorption and dispersion z (mm) The HPD in the cell partially filled with aerogel

  26. FIDS from the HPD in the cell partially filled with aerogel amplitude time (s)

  27. WB/2p (kHz) T/Tc, T/Tca

  28. Frequency of oscillations vs amount of aerogel (results of computer simulations of Leggett equations) k0 m1 m2 Frequency (Hz) k1 k2 filling factor cell length=1.8 mm

  29. Free induction decay signal (FIDS) recorded by digital oscilloscope Time (ms)

  30. FIDS amplitude time (ms)

  31. Pure 3He + aerogel: 2 solid monolayers of 3He on surface of aerogel strands: 4He replaces 3He atoms at surface: NMR signal is determined only by liquid 3He

  32. amplitude time (s) FIDS from the HPD with initial length of 4.9 mm

  33. Oe Signal amplitude Oe z (mm)

More Related