Title: Imbalanced Fermi Gases
1Imbalanced Fermi Gases
Masud Haque Koos Gubbels Mathijs Romans Arnaud
Koetsier Henk Stoof Guthrie Partridge Wenhui
Li Yean-an Liao Randy Hulet
Utrecht University
2Imbalanced Fermi Mixture (I)
- Atomic Fermi mixtures in an optical trap
3Imbalanced Fermi Mixture (II)
- Up to recently only . However, the
most recent experiments do not have this
condition any longer. This means that
4MIT Science experiment (I)
- Uses rotation to create vortices and measures
density profiles after expansion and magnetic
field sweep
M.W. Zwierlein et al., Science 311, 492 (2006).
5MIT Science experiment (II)
M.W. Zwierlein et al., Science 311, 492 (2006).
6Rice Science experiment (I)
G.B. Partridge et al., Science 311, 503 (2006).
7Rice Science experiment (II)
G.B. Partridge et al., Science 311, 503 (2006).
8Zero Temperature Theory (I)
- Using the BCS ansatz we find for the homogeneous
case
9Zero Temperature Theory (II)
- Local-density theory and BCS ansatz
10Zero Temperature Theory (III)
- Comparison with Rice experiment
M. Haque and H.T.C. Stoof, PRA 74, 011602(R)
(2006). See also F. Chevy, PRL 96, 130401
(2006) and T.N. De Silva and E.J. Mueller, PRA
73, 051602(R) (2006).
11MIT Nature experiment
- Measures density
- profiles after
- expansion
M.W. Zwierlein et al., Nature 442, 54 (2006).
12Nonzero Temperature Theory (I)
- Proposed (universal) phase diagram
K.B. Gubbels et al., PRL 97, 210402 (2006).
13Nonzero Temperature Theory (II)
- In-situ density profiles are again calculated in
local-density approximation
K.B. Gubbels et al., PRL 97, 210402 (2006).
14Nonzero Temperature Theory (III)
- Comparison with MIT experiment
K.B. Gubbels et al., PRL 97, 210402 (2006).
15Rice PRL experiment (I)
G.B. Partridge et al., PRL 97, 190407 (2006).
16Rice PRL experiment (II)
- Comparison between theory and experiment
G.B. Partridge et al., PRL 97, 190407 (2006).
17Rice PRL experiment (III)
- Comparison between low and high
temperature
G.B. Partridge et al., PRL 97, 190407 (2006).
18Rice PRL experiment (IV)
19Conclusions and Outlook
- Our (universal) phase diagram is able to explain
the contradictions between the MIT and Rice
experiments. - Remaining problem is the absolute temperature
scale. Requires inclusion of fluctuations into
the theory. We are working on this! - Imbalanced Fermi gases in optical lattices and
neutron stars!
20The Quantum Fluids and Solids Group
- Students Koos Gubbels
- Mathijs Romans
- Arnoud Koetsier
- Postdocs Masud Haque (Dresden)
- Pietro Massignan
-
- Staff Henk Stoof
- Special thanks
- Randy Hulet