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Tesi etd-04092008-120324


Thesis type
Tesi di dottorato di ricerca
Author
SIAS, CARLO
URN
etd-04092008-120324
Title
Control of matter wave tunneling in an optical lattice
Settore scientifico disciplinare
FIS/03
Corso di studi
FISICA APPLICATA
Commissione
Relatore Prof. Arimondo, Ennio
Parole chiave
  • optical lattice
  • Bose Einstein condensate
  • BEC
  • tunneling
Data inizio appello
07/04/2008;
Consultabilità
completa
Riassunto analitico
Bose Einstein condensation is a phase transition emerging in systems of<br>integer-spin particles whose temperature is lowered under a critical value. One of the signatures of this phenomenon is the emergence of a<br>phase coherence through the whole system, so that its behaviors can be de-<br>scribed by single particle wavefunctions. After two-decades-long efforts in<br>the development of laser cooling techniques, Bose-Einstein conden-<br>sation was achieved in dilute gases of neutral atoms. Apart from its<br>fundamental interest, this experimental result opened the way to the study<br>of the quantum world with macroscopic samples.<br>In parallel with the research on cooling, the developments on laser physics<br>led to the creation of artificial atomic crystals by use of light-induced periodic<br>potentials, so-called optical lattices. These potentials were applied to<br>Bose-Einstein condensates shortly after their discovery.<br>In the last decade, a large part of the BEC community showed a strong<br>interest in ultra-cold atoms loaded into optical lattices. The periodic<br>potentials proved to be an exceptional tool for manipulating BECs, because<br>of their feasibility in the laboratory with the present technology, and be-<br>cause only few parameters govern the behavior of the sample. In fact, this<br>is described by the interplay between two fundamental physical processes:<br>atom-atom interactions and quantum tunneling.<br>The unifying theme of this thesis is the quantum tunneling in an ultra-cold<br>gas loaded into an optical lattice. In the experiments that we performed we<br>were able to observe effects due to quantum tunneling as well as to develop<br>experimental techniques to control it.
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