Presentation is loading. Please wait.

Presentation is loading. Please wait.

BOSE-EINSTEIN CONDENSATES A REVIEW OF EXPERIMENTAL RESULTS

Similar presentations


Presentation on theme: "BOSE-EINSTEIN CONDENSATES A REVIEW OF EXPERIMENTAL RESULTS"— Presentation transcript:

1 BOSE-EINSTEIN CONDENSATES A REVIEW OF EXPERIMENTAL RESULTS
VORTEX STRUCTURES IN BOSE-EINSTEIN CONDENSATES A REVIEW OF EXPERIMENTAL RESULTS R. Srinivasan Raman Research Institute, Bangalore

2 CONDENSATE WITH A VORTEX
ORDER PARAMETER OF THE CONDENSATE F(r,t) = n(r,t) exp(i S(r,t) V = (h/m) grad S ; V = 0  V dr = (h/m)   S  dr = k (h/m) k AN INTEGER  0 IMPLIES A CONDENSATE WITH A VORTEX

3 GENERATION OF VORTICES
1. Rotating a trap containing a thermal cloud and simultaneously cooling the cloud below TC 2. By stirring a condensate with an optical spoon. 3. By imprinting a phase on the condensate dynamically or topologically.

4 DETECTION 1. Vortices are detected by ballistically allowing the condensate to expand and absorption imaging it. Core diameter increases one order by expansion. 2. Rotation of the condensate detected by measuring its aspect ratio in a plane containing the axes of rotation.

5 3. The angular momentum of the condensate is
measured By measuring the difference in surface mode frequencies of l =2, m = +2 and m = -2 modes. P.C. Haljan et al., (2001), PRL, 87,

6 FIRST EXPERIMENTAL PROOF
OF VORTICES K.W. Madison et al, (2000), PRL 84, 806

7 RESONANT NUCLEATION OF VORTICES BY SURFACE DEFORMATION.
C. Raman et al. (2001), PRL 87,

8 If the vortex is stirred by a narrow optical spoon then
vortices continuously increase above a critical velocity. GROWTH AND DECAY OF VORTEX LATTICE a ms e 1 s b f 5 s c g. 10 s d h 40 s J.R. Abo-shaeer et al., (2001), Science, 292,476

9 Nc/N 0.78 0.75 0.71 0.62 J.R. Abo-shaeer et al (2002), PRL, 88,

10 NON-EQUILIBRIUM EFFECTS DUE TO COMPRESSION OF A VORTEX LATTICE
No Surface mode Surface mode l = 2, m = Surface mode l = 2, m = +2 No rotation relative Surface deformation rotates at Surface deformation rotates at to vortex lattice Hz relative to vortex lattice Hz relative to vortex lattice Engels et al. (2002), PRL, 89,

11 TKACHENKO OSCILLATIONS IN VORTEX LATTICE
I.Coddington et al. (2003), PRL,

12 TKACHENKO OSCILLATIONS: TRANSITION FROM T-F TO QUANTUM HALL REGIME
V.Schweikhard etal (2004), PRL 040404

13 GIANT VORTICES AT HIGH SPEEDS OF ROTATION
Laser pulse applied for 2.5 s. Hold time in trap (a) 0.5 s; (b) 10.5 s; (c) 20.5 s; and (d) 30.5 s Engels et al. (2003), PRL, 90, 170405 Laser on (b) 14 s; (c) 15 s; (d) 20 s; (e) 22s (f) 23 s; (g) 40 s and (h) 70 s

14 POSSIBLE FUTURE WORK 1.APPROACH TO QUANTUM HALL AND FRACTIONAL QUANTUM HALL REGIMES 2. GIANT VORTICES : FORMATION AND STABILITY 3. VORTICES IN SPINOR CONDENSATES: TEXTURE IN VORTICES: SKYRMIONS

15

16


Download ppt "BOSE-EINSTEIN CONDENSATES A REVIEW OF EXPERIMENTAL RESULTS"

Similar presentations


Ads by Google