solitons in atomic bose einstein condensates bec n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Solitons in atomic Bose-Einstein Condensates (BEC) PowerPoint Presentation
Download Presentation
Solitons in atomic Bose-Einstein Condensates (BEC)

Loading in 2 Seconds...

play fullscreen
1 / 46

Solitons in atomic Bose-Einstein Condensates (BEC) - PowerPoint PPT Presentation


  • 280 Views
  • Uploaded on

Solitons in atomic Bose-Einstein Condensates (BEC). Gediminas Juzeliūnas Institute of Theoretical Physics and Astronomy of Vilnius University, Vilnius, Lithuania. Collaboration. P. Öhberg , Heriot-Watt University , Edinburgh, Scotland

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Solitons in atomic Bose-Einstein Condensates (BEC)' - ostinmannual


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.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
solitons in atomic bose einstein condensates bec

Solitons in atomicBose-Einstein Condensates(BEC)

Gediminas Juzeliūnas

Institute of Theoretical Physics and Astronomy of Vilnius University, Vilnius, Lithuania

collaboration
Collaboration
  • P. Öhberg, Heriot-Watt University, Edinburgh, Scotland
  • J. Ruseckas, Institute of Theoretical Physics and Astronomy of Vilnius University
  • M. Fleischhauer, Technische Universität Kaiserslautern, Germany
outline
OUTLINE
  • Ultra-cold atomic gases
  • Atomic Bose-Einstein condensates (BEC)
  • Solitons & solitons in atomic BEC
  • Creation of solitons in atomic BEC
  • A new method of creating solitons in BEC
  • Conclusions
non linear schr dinger equation gross pitaevskii
Non-linear Schrödinger equation(Gross-Pitaevskii)
  • Wavefunction of a condensate

For simplicity V=0 (no trapping potential):

non linear schr dinger equation gross pitaevskii1
Non-linear Schrödinger equation(Gross-Pitaevskii)
  • Wavefunction of the condensate
  • Interaction strength
  • between the atoms
non linear schr dinger equation gross pitaevskii2
Non-linear Schrödinger equation(Gross-Pitaevskii)
  • Wavefunction of the condensate

Linear wave equation

Wave-packet is spreading out

non linear schr dinger equation gross pitaevskii3
Non-linear Schrödinger equation(Gross-Pitaevskii)
  • Wavefunction of the condensate

Non-linear wave equation

Non-spreading wave-packets (solitons) are possible

non linear schr dinger equation gross pitaevskii4
Non-linear Schrödinger equation(Gross-Pitaevskii)
  • Wavefunction of the condensate

Bright soliton

Dark soliton

non linear schr dinger equation gross pitaevskii5
Non-linear Schrödinger equation(Gross-Pitaevskii)
  • Wavefunction of the condensate

Bright soliton

Dark soliton

What is a bright and a dark soliton?

slide19

Bright soliton

Dark soliton

first observation of bright solitons 1844 j scott russell
First observation of (bright) solitons (1844, J. Scott Russell )

Observed a solitary water wave

in a water canal near Edinburgh

John Scott Russell (1808 – 1882)

currently
Currently
  • Optical solitons (bright, dark) since the 60’s

(Depends on the sign of non-linearity)

  • Solitons in BEC (dark, bright), since 1999
    • Rb, Na – dark solitons (κ>0)
    • Li – bright solitons (κ<0)
usual way to create a dark soliton in bec
Usual way to create a (dark) soliton in BEC
  • To imprint the phase

(by illuminating a half

of the BEC)

drawbacks
Drawbacks
  • Not very sharp phase slip
  • No hole in the density
  • Sensitive to the duration of illumination
    • Not robust method
our method adiabatic passage in a tripod configuration
Our method:Adiabatic passage in a tripod configuration
  • Robust
  • Both solitons and soliton molecules can be produced
adiabatic passage
Adiabatic passage

Λ configuration:

slide33
Dark state:Atom remains in the dark state: Adiabatic passage(STIRAP) - a smooth transition 1→2by changing the ratio
dark state atom remains in the dark state adiabatic passage 1 2 1 double stirap two stiraps
Dark state:Atom remains in the dark state: Adiabatic passage1→2 →1Double STIRAP (two STIRAPs)
dark state atom remains in the dark state adiabatic passage 1 2 1 phase slip a problem
Dark state:Atom remains in the dark state: Adiabatic passage1→2 →1πphase slip A problem
slide37
Dark state:Atom remains in the dark state: Adiabatic transition 1→2 →1πphase slip The problem by-passed
tripod configuration
Tripod configuration
  • Two degenerate dark states:

e.g.,

J. Ruseckas, G. Juzeliūnas and P.Öhberg, and M. Fleischhauer, Phys. Rev. Letters 95, 010404 (2005).

slide40

A suggested setup to create solitons in BEC (Double STIRAP with a support beam 3)

BEC initially in the state 1:

π phase imprinting on the BEC in the state 1:

after the sweeping
After the sweeping
  • Phase imprinting → (dark) soliton formation
  • πphase slip;
  • a hole in the density
after the sweeping1
After the sweeping
  • Phase imprinting → (dark) soliton formation
  • More specifically - dark-bright soliton pair
  • πphase slip;
  • a hole in the density
a soliton molecule two component dark soliton dark dark soliton pair
A soliton molecule - two component dark soliton (dark-dark soliton pair)
  • Both components 1 and 2 are populated

after the sweeping (with a π phase slip)

Subsequently the solitons oscillate:

conclusions
Conclusions
  • A new method of creating solitons
  • Robust
  • Creation of soliton molecules is possible