G5 Artikkeliväitöskirja
Radio-frequency spectroscopy of superfluid Fermi gas (2006)
Kinnunen, J. (2006). Radio-frequency spectroscopy of superfluid Fermi gas [Doctoral dissertation]. Jyväskylän yliopisto. Research report / Department of Physics, University of Jyväskylä, 12/2006. http://urn.fi/URN:ISBN:978-951-39-3177-3
JYU-tekijät tai -toimittajat
Julkaisun tiedot
Julkaisun kaikki tekijät tai toimittajat: Kinnunen, Jami
ISBN: 951-39-2668-0
eISBN: 978-951-39-3177-3
Lehti tai sarja: Research report / Department of Physics, University of Jyväskylä
ISSN: 0075-465X
Julkaisuvuosi: 2006
Sarjan numero: 12/2006
Kustantaja: Jyväskylän yliopisto
Kustannuspaikka: Jyväskylä
Julkaisun kieli: englanti
Pysyvä verkko-osoite: http://urn.fi/URN:ISBN:978-951-39-3177-3
Julkaisun avoin saatavuus: Avoimesti saatavilla
Julkaisukanavan avoin saatavuus:
Julkaisu on rinnakkaistallennettu (JYX): http://urn.fi/URN:ISBN:978-951-39-3177-3
Lisätietoja: Jami Kinnunen Radio-frequency spectroscopy of superfluid Fermi gas JYFL Research Report No 12/2006 (2006) xx
Tiivistelmä
Radio-frequency and laser fields provide a coherent and well understood tool for
manipulating atomic gases. However, new phenomena are expected and have already
been seen experimentally when the alkali atoms become strongly interacting.
Here we use a simple perturbative treatment of the atom-rf-field coupling for
studying the spectroscopy of a strongly interacting gas. At ultracold temperatures
fermionic atoms become paired in analogy to electrons in superconductors. The resulting
binding energy, or the pairing gap, can be observed as a shift in the radiofrequency
spectrum. With strong interactions, the fermions begin pairing already
above the critical superfluid transition temperature. The radio-frequency spectroscopy
grants a way to study these fluctuation effects quantitatively.
The inhomogeneous trapping potential of the atom cloud also adds its own
flavour, resulting in distinct mesoscopic effects in the radio-frequency spectra. Our
theoretical models are in very good agreement with the experimental results. First
order perturbation theory provides qualitatively correct lineshapes, and our generalised
perturbative approach gives quantitatively correct magnitudes for the transfer
rates.
The inhomogeneity plays an important part also in more exotic systems in
which the simple BCS-type pairing of atoms is prevented by polarising the gas. Superfluidity
and phase separation in such spin-imbalanced gases has been experimentally
observed. We have suggested the use of radio-frequency spectroscopy for
observing exotic polarised superfluid states, present at the edges of the atom cloud.
YSO-asiasanat: atomifysiikka; spektroskopia
Liittyvät organisaatiot
OKM-raportointi: Kyllä
Alustava JUFO-taso: Not rated
