News

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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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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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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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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Tue January 1, 2013

All-Optical Switch and Transistor Gated by One Stored Photon

In this paper we demonstrate an all-optical switch gated by one stored photon. Using an atomic ensemble trapped inside an optical cavity, we store a photon incident transverse to the cavity in the atomic ensemble, thereby changing the state of one atom. This atom then blocks the cavity for photons incident along the cavity axis....
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Tue January 1, 2013

Many-body Localization with Dipoles

Systems of strongly interacting dipoles offer an attractive platform to study many-body localized phases, owing to their long coherence times and strong interactions. We explored conditions under which such localized phases persisted in the presence of power-law interactions and supplemented our analytic treatment with numerical evidence of localized states in one dimension. We proposed several...
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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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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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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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Tue January 1, 2013

Nanometer-scale Thermometry in a Living Cell

Sensitive probing of temperature variations on nanometre scales is an outstanding challenge in many areas of modern science and technology. In particular, a thermometer capable of subdegree temperature resolution over a large range of temperatures as well as integration within a living system could provide a powerful new tool in many areas of biological, physical...
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