News

Wed January 1, 2014

Scattering Resonances and Bound States for Strongly Interacting Rydberg Polaritons

We provided a theoretical framework, which described slow-light polaritons interacting via atomic Rydberg states. We used a diagrammatic method to analytically derive the scattering properties of two polaritons. We identified new parameter regimes where polariton-polariton interactions were repulsive. Furthermore, in the regime of attractive interactions, we identified multiple two-polariton bound states, calculated their dispersion, and...
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Wed January 1, 2014

Properties of the ground 3F2 state and the excited 3P0 state of atomic thorium in cold collisions with 3He

We measure inelastic collisional cross sections for collisions between thorium (Th) and helium. We determine for Th 3F2-He the ratio of the momentum-transfer to Zeeman relaxation cross sections for collisions to be g~500 at 800 mK. For Th 3P0-He collisions, we observe no measureable quenching of this metastable state, even after 106 collisions. This allowed...
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Wed January 1, 2014

Time-resolved magnetic sensing with electronic spins in diamond

One of the most promising applications of quantum information is in precision metrology. In the past year we focused on magnetic sensing with NV centers in diamond, in particular focusing on techniques to extend magnetic field sensing at the nano-scale to time-dependent reconstruction of magnetic fields and spectroscopy.
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Wed January 1, 2014

Quantum Interference Between Independent Reservoirs in Open Quantum Systems

When a quantum system interacts with multiple reservoirs, the environmental effects are usually treated in an additive manner. We showed that that assumption breaks down for non-Markovian environments that have finite memory times. Specifically, we demonstrated that quantum interferences between independent environments could qualitatively modify the dynamics of the physical system. We illustrated that effect...
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Wed January 1, 2014

Buffer-gas loaded magneto-optical traps for Yb, Tm, Er, and Ho

Novel physics in areas like quantum information, cold controlled chemistry and precision measurements is predicted to be accessible with molecules at temperatures in the mK regime. These approaches require molecular beam sources which are unavailable at present. In particular, providing cold, slow and bright beams of a general set of molecules, ideally independent of their...
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Wed January 1, 2014

Quantum Nanophotonic Phase Switch with a Single Atom

In analogy to transistors in classical electronic circuits, a quantum optical switch is an important element of quantum circuits and quantum networks. Operated at the fundamental limit where a single quantum of light or matter controls another field or material system, it may enable fascinating applications such as long-distance quantum communication, distributed quantum information processing and...
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Mon November 4, 2013

Professor Daniel Kleppner, 2014 Franklin Institute Laureate

A research collaboration including CUA investigators at Harvard.
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