Our group studies ultracold gases near Absolute Zero temperature. At temperatures a million times colder than interstellar space, and at densities a million times thinner than air, quantum mechanics takes center stage: Atoms behave as waves, they interfere like laser light, and form novel states of matter, such as Bose-Einstein condensates and fermionic superfluids. In such a Fermi gas, atoms team up in pairs that can flow without friction. This has analogies to electron pairs in a superconductor that transport current without resistance. In contrast to bulk materials, we can freely tune the interaction between atoms and, for example, explore the crossover from a Bose-Einstein condensate of tightly bound molecules to a Bardeen-Cooper-Schrieffer superfluid of long-range fermion pairs. Our goal is to use these gases as model systems for strongly interacting quantum matter, from High-T_c superconductors to Neutron Stars.

HighlightS

October 13, 2009: Bose-Einstein Condensation of 41-K in Fermi I

The first degenerate gas in our new multi-species apparatus "Fermi I" has seen the (laser-)light of day: A Bose-Einstein Condensate of 41-K atoms. The apparatus allows to cool all potassium species, lithium and sodium.

September 10, 2009: André Schirotzek wins MIT's Martin Deutsch Prize

Congratulations to André for winning MIT's Deutsch Prize for Excellence in Experimental Physics!

June 8, 2009: Observation of Fermi Polarons

We have observed Fermi Polarons, dressed spin down impurities swimming in a Fermi sea of spin up atoms. These polarons constitute the quasiparticles in the Fermi liquid of strongly interacting, imbalanced Fermi mixtures. Remarkably, despite resonant interactions between the bare particles, the interactions between polarons are found to be weak. Read more in our PRL-article and in the Viewpoint Commentary by F. Chevy in Physics.

Review

Review on Ultracold Fermi Gases:
Wolfgang Ketterle and Martin W. Zwierlein

Making, probing and understanding ultracold Fermi gases

in Ultracold Fermi Gases, Proceedings of the International School of Physics  “Enrico Fermi”, Course CLXIV,

eds. M. Inguscio, W. Ketterle, and C. Salomon (Amsterdam, IOS Press, 2008), e-print: arXiv: 0801.2500.

 

FUNDING

CUA	NSF	AFOSR - MURI	Sloan Foundation

The group of Prof. Martin Zwierlein is part of the Center for Ultracold Atoms, the Research Laboratory of Electronics and the Department of Physics, at the Massachusetts Institute of Technology.