News: Research Highlights

Sat January 1, 2011

Revealing the Superfluid Lambda Transition in the Unviersal Thermodynamics of a Unitary Fermi Gas

Fermi gases, collections of fermions such as neutrons and electrons, are found throughout nature, from solids to neutron stars. Interacting Fermi gases can form a superfluid or, for charged fermions, a superconductor. We have directly observed the superfluid phase transition in a strongly interacting Fermi gas via high-precision measurements of the local compressibility, density and...
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Sat January 1, 2011

Feynman diagrams versus Feynman quantum emulator

Precise understanding of strongly interacting fermions, from electrons in modern materials to nuclear matter, presents a major goal in modern physics. However, the theoretical description of interacting Fermi systems is usually plagued by the intricate quantum statistics at play. Here we present a cross-validation between a new theoretical approach, Bold Diagrammatic Monte Carlo (BDMC), and...
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Sat January 1, 2011

Cold Heteromolecular Dipolar Collisions

We present the first experimental observation of cold collisions between two different species of neutral polar molecules, each prepared in a single internal quantum state. Combining for the first time the techniques of Stark deceleration, magnetic trapping, and cryogenic buffer gas cooling allows the enhancement of molecular interaction time by 10,000. This has enabled an...
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Sat January 1, 2011

Quantum degenerate Bose-Fermi mixture of chemically different atomic species with widely tunable interactions

We have created a quantum degenerate Bose-Fermi mixture of 23Na and 40K with widely tunable interactions via broad interspecies Feshbach resonances. Twenty Feshbach resonances between 23Na and 40K were identified. The large and negative triplet background scattering length between 23Na and 40K causes a sharp enhancement of the fermion density in the presence of a...
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Sat January 1, 2011

A cryogenic beam of refractory, chemically reactive molecules with expansion cooling

Atomic and molecular beams have been valuable tools for precision measurement of atomic and molecular spectra for the past several decades.  In order to achieve good signal to noise in a beam spectroscopy experiment, it is important to have high fluxes, low forward velocity (to increase interaction time), and, in the case of molecules, cold...
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Fri January 1, 2010

Coherent recoilless scattering of atoms

Two papers were finished recently on the subject of recoilless scattering from a gas and scattering from atoms in an optical lattice as a probe of the quantum state of the lattice.
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Fri January 1, 2010

Orientation-Dependent Entanglement Lifetime in a Squeezed Atomic Clock

Atomic Clock Beats the Quantum Limit

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Fri January 1, 2010

Probing quantum phase transitions at the single-atom level

Physicists Get an Up–Close Look at Synthetic Quantum Materials

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