Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Adiabatic guiding of matter waves
KTH, Superseded Departments, Physics.
2003 (English)Doctoral thesis, comprehensive summary (Other scientific)
Abstract [en]

Recent efforts in the field of ultracold atoms have goneinto creating wave guides of sub-micron sizes. In this thesis,the quantum dynamics of matter waves in such confiningpotential structures with minima extended in space isinvestigated. A general framework based upon the separation ofthe wave function for the quantum particle using a discrete setof mode functions is introduced to reduce the dimensionality ofthe problem. Conditions for propagation in the form ofindependent modes, i.e. adiabatic propagation, are determinedfor the case of matter waves with spatially varying width andfound to be connected to the diffraction of matter wavesthrough a dimensionless parameter, the Fresnel parameter.

Further, the analysis is extended to include situationswhere a transition to completely non-adiabatic dynamics takesplace. Here it is found that focusing of matter waves due toenergy redistribution at the end of adiabatic guiding isdetermined by the Fresnel parameter found earlier. In theadiabatic regime, the essential dynamics in the directiontransverse to the minimal valley of the guiding potentialstructure occurs at a time-scale much shorter than that ofchanges in the propagating direction. As a result of this,reection of matter waves is likely to occur unless the changesare made over very long distances.

The formalism of adiabatic propagation is also applied thesituation of splitting of matter waves in potential structures.It is found that the adiabaticity criteria are identical tothose for a single guide of spatially varying width. Aformulation of adiabatic splitting in terms of states localizedclose to either of the two minima is developed. The inuence oflongitudinal localization on the splitting of coherentsuperposition states is examined and found to be described by asimple analytical expression.

Place, publisher, year, edition, pages
Stockholm: Fysik , 2003. , 47 p.
Series
Trita-FYS, ISSN 0280-316X ; 2003:13
Identifiers
URN: urn:nbn:se:kth:diva-3534ISBN: OAI: oai:DiVA.org:kth-3534DiVA: diva2:9350
Public defence
2003-05-30
Note
NR 20140805Available from: 2003-05-27 Created: 2003-05-27Bibliographically approved

Open Access in DiVA

fulltext(623 kB)420 downloads
File information
File name FULLTEXT01.pdfFile size 623 kBChecksum MD5
bf0753590df09795db4ac6676d1c54171477150ed20bb5eb3fc2ef054a77d1cc637c5a4e
Type fulltextMimetype application/pdf

By organisation
Physics

Search outside of DiVA

GoogleGoogle Scholar
Total: 420 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

urn-nbn

Altmetric score

urn-nbn
Total: 254 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf