News

Tue January 1, 2013

Spin-Orbit Suppression of Cold Inelastic Collisions of Aluminum and Helium

Cold collisions between atoms play a critical role in much of atomic physics, being responsible for few-body interactions, thermalization, trap loss and decoherence.  The development of a detailed understanding of collisions is therefore crucial to the continued expansion of the field into new atomic systems, an expansion that has already led to the discovery of...
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Research Highlights
Tue January 1, 2013

Beyond Universal Long-Range van der Waals Interactions with Ultracold 6Li2 Molecules

We have found that collisional loss of ultracold 6Li2 molecules can be determined by physics beyond universal long-range van der Waals interactions [1]. Starting with a degenerate Fermi gas of 6Li produced by sympathetic cooling with bosonic 23Na, we form Li2 molecules by a magnetic field sweep around a narrow Feshbach resonance. The resulting molecules...
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Research Highlights
Tue January 1, 2013

Single-photon Nonlinearities in Two-mode Optomechanics

We presented a detailed theoretical analysis of a weakly driven, multimode optomechanical system, in which two optical modes were strongly and near-resonantly coupled to a single mechanical mode via a three-wave mixing interaction. We calculated one- and two-time intensity correlations of the two optical fields and compared them to analogous correlations in atom-cavity systems. Nonclassical...
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Research Highlights
Tue January 1, 2013

Progress on Laser Cooling of CaF

The internal structure and the long-range dipole-dipole interactions of ultracold polar molecules open new avenues in studying physics such as the quantum simulation of strongly correlated Hamiltonians, ultracold controlled chemistry or precision measurements. At present, a reliable general method to produce an ultracold sample of molecules is desired, but not available. The goal of this...
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Research Highlights
Tue January 1, 2013

A Quantum Network of Clocks

The development of precise atomic clocks has led to many scientific and technological advances that play an increasingly important role in modern society. Shared timing information constitutes a key resource for positioning and navigation with a direct correspondence between timing accuracy and precision in applications such as the Global Positioning System (GPS). By combining precision...
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Research Highlights
Tue January 1, 2013

Coherence and Raman Sideband Cooling of a Single Atom in an Optical Tweezer

We investigated quantum control of a single atom in a tightly focused optical tweezer trap. We showed that inevitable spatially varying polarization gave rise to significant internal-state decoherence but that the effect could be mitigated by an appropriately chosen magnetic bias field. That enabled Raman sideband cooling of a single atom close to its three-dimensional...
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Research Highlights
Tue January 1, 2013

Phonon-induced Spin-Spin Interactions in Diamond Nanostructures: Application to Spin Squeezing

We proposed and analyzed a novel mechanism for long-range spin-spin interactions in diamond nanostructures. The interactions between electronic spins, associated with nitrogen-vacancy centers in diamond, were mediated by their coupling via strain to the vibrational mode of a diamond mechanical nanoresonator. That coupling resulted in phonon-mediated effective spin-spin interactions that could be used to generate...
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Research Highlights
Tue January 1, 2013

Timekeeping with Electronic Spin States in Diamond

Frequency standards based on atomic states, such as Rb or Cs vapors, or single-trapped ions, are the most precise measures of time. We proposed and analyzed a precision oscillator approach based upon spins in a solid-state system, in particular, the nitrogen-vacancy defect in single-crystal diamond. We showed that that system could have stability that approached...
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Research Highlights
Tue January 1, 2013

Keldysh Approach for Non-equilibrium Phase Transitions in Quantum Optics: Beyond the Dicke Model in Optical Cavities

We investigated nonequilibrium phase transitions for driven atomic ensembles interacting with a cavity mode and coupled to a Markovian dissipative bath. In the thermodynamic limit and at low frequencies, we showed that the distribution function of the photonic mode was thermal, with an effective temperature set by the atom-photon interaction strength. That behavior characterized the...
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Research Highlights
Tue January 1, 2013

Single-photon Nonlinear optics with Graphene Plasmons

We showed that it was possible to realize significant nonlinear optical interactions at the few photon level in graphene nanostructures. Our approach took advantage of the electric field enhancement associated with the strong confinement of graphene plasmons and the large intrinsic nonlinearity of graphene. Such a system could provide a powerful platform for quantum nonlinear...
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News type:
Research Highlights