umu.sePublications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • 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
Experimental and Numerical Investigations of Ultra-Cold Atoms
Umeå University, Faculty of Science and Technology, Physics.
2007 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

I have been one of the main responsible for building a new laboratory for Bose-Einstein condensation with 87Rb. In particular, the experimental setup has been designed for performing experiments with Bose-Einstein condensates load into optical lattices of variable geometries.

All parts essential for Bose-Einstein condensation are in place. Atoms are collected in a magneto-optical trap, transferred to another vacuum chamber, with better vacuum, and trapped in another magneto-optical trap. Atoms are successfully transferred to a dark magnetic trap, and system for diagnostics with absorption imaging has been realized. We have not yet been able to form a Bose-Einstein condensate, due to a range of technical difficulties.

Equipment for alignment of optical lattices with flexible geometry has been designed, built, and tested. This tool has been proven to work as desired, and there is a great potential for a range of unique experiments with Bose-Einstein condensates in optical lattices of various geometries, including superlattices and quasi-periodic lattices.

Numerical studies have been made on anisotropic optical lattices, and the existence of a transition between a 2D superfluid phase and a 1D Mott-insulating phase has been confirmed. We have shown that the transition is of Berezinskii-Kosterlitz-Thouless type. In another numerical study it has been shown that using stimulated Raman transitions is a practical method for transferring atoms between states in a double optical lattice. Thus, it will be possible to transfer populations between the lattices, with further applications in qubit read/write operations.

Place, publisher, year, edition, pages
Umeå: Fysik , 2007. , 50 p.
Keyword [en]
Ultracold atoms, optical lattices, Bose-Einstein condensation, quantum phase transitions
National Category
Physical Sciences
Identifiers
URN: urn:nbn:se:umu:diva-1453ISBN: 978-91-7264-466-3 (print)OAI: oai:DiVA.org:umu-1453DiVA: diva2:141127
Public defence
2007-12-17, N450, Naturvetarhuset, 13:00 (English)
Opponent
Supervisors
Available from: 2007-11-26 Created: 2007-11-26 Last updated: 2009-06-30Bibliographically approved
List of papers
1. A set-up for flexible geometry optical lattices
Open this publication in new window or tab >>A set-up for flexible geometry optical lattices
Show others...
2008 (English)In: European Physical Journal: Applied physics, ISSN 1286-0042, E-ISSN 1286-0050, Vol. 42, 269-273 p.Article in journal (Refereed) Published
Abstract [en]

We have developed an alignment tool for optical lattices with arbitrary beam angles, allowing for optical potentials with a range of geometries and topographies. A calibration procedure has been introduced, giving a precision of 10 mrad in the chosen beam angle, and a high degree of flexibility. The tool has been tested in simplified experiments on the confinement and expansion of cold atoms in one-dimensional and two-dimensional optical lattices, and has proved to work well.

Identifiers
urn:nbn:se:umu:diva-10492 (URN)doi:10.1051/epjap:2008086 (DOI)
Available from: 2008-09-17 Created: 2008-09-17 Last updated: 2017-12-14Bibliographically approved
2. Transition from a Two-Dimensional Superfluid to a One-Dimensional Mott Insulator
Open this publication in new window or tab >>Transition from a Two-Dimensional Superfluid to a One-Dimensional Mott Insulator
Show others...
2007 (English)In: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 99, no 11, 110401- p.Article in journal (Refereed) Published
Abstract [en]

A two-dimensional system of atoms in an anisotropic optical lattice is studied theoretically. If the system is finite in one direction, it is shown to exhibit a transition between a two-dimensional superfluid and a one-dimensional Mott insulating chain of superfluid tubes. Monte Carlo simulations are consistent with the expectation that the phase transition is of Kosterlitz-Thouless type. The effect of the transition on experimental time-of-flight images is discussed.

Identifiers
urn:nbn:se:umu:diva-18169 (URN)10.1103/PhysRevLett.99.110401 (DOI)
Available from: 2007-11-28 Created: 2007-11-28 Last updated: 2017-12-14Bibliographically approved
3. One-dimensional phase transitions in a two-dimensional optical lattice
Open this publication in new window or tab >>One-dimensional phase transitions in a two-dimensional optical lattice
Show others...
2008 (English)In: European Physical Journal D: Atomic, Molecular and Optical Physics, ISSN 1434-6060, E-ISSN 1434-6079, Vol. 49, no 2, 223-230 p.Article in journal (Refereed) Published
Abstract [en]

A phase transition for bosonic atoms in a two-dimensional anisotropic optical lattice is considered. If the tunnelling rates in two directions are different, the system can undergo a transition between a two-dimensional superfluid and a one-dimensional Mott insulating array of strongly coupled tubes. The connection to other lattice models is exploited in order to better understand the phase transition. Critical properties are obtained using quantum Monte Carlo calculations. These critical properties are related to correlation properties of the bosons and a criterion for commensurate filling is established.

National Category
Atom and Molecular Physics and Optics
Identifiers
urn:nbn:se:umu:diva-10486 (URN)10.1140/epjd/e2008-00152-9 (DOI)
Available from: 2008-09-16 Created: 2008-09-16 Last updated: 2017-12-14Bibliographically approved
4. Raman transitions in double optical lattices
Open this publication in new window or tab >>Raman transitions in double optical lattices
(English)Manuscript (Other academic)
Identifiers
urn:nbn:se:umu:diva-2837 (URN)
Available from: 2007-11-26 Created: 2007-11-26 Last updated: 2010-12-20Bibliographically approved

Open Access in DiVA

fulltext(2514 kB)1555 downloads
File information
File name FULLTEXT01.pdfFile size 2514 kBChecksum SHA-1
0bd2892240bc79cc9fa6bcf9017dd1e6925058e72fedc358257efbd69a2dc67675bdf272
Type fulltextMimetype application/pdf

Search in DiVA

By author/editor
Rehn, Magnus
By organisation
Physics
Physical Sciences

Search outside of DiVA

GoogleGoogle Scholar
Total: 1555 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

isbn
urn-nbn

Altmetric score

isbn
urn-nbn
Total: 549 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • 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