News: Research Highlights

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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Research Highlights
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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News type:
Research Highlights
Wed January 1, 2014

Coherent Optical Transitions in Implanted Nitrogen-vacancy Centers

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News type:
Research Highlights
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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Research Highlights
Tue January 1, 2013

Polaronic Model of Two-level Systems in Amorphous Solids

While two-level systems (TLSs) are ubiqitous in solid state systems, microscopic understanding of their nature remains an outstanding problem. Conflicting phenomenological models are used to describe TLSs in seemingly similar materials when probed with different experimental techniques. Specifically, bulk measurements in amorphous solids have been interpreted using the model of a tunneling atom or group...
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Research Highlights
Tue January 1, 2013

Coupling of a Single Trapped Atom to a Nanoscale Optical Cavity

In this paper in collaboration with the Lukin group, we demonstrate for the first time deterministic coupling of a trapped atom to a nanophotonic resonator. For details see Lukin’s report.
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Research Highlights
Tue January 1, 2013

Collectively Enhanced Interactions in Solid-state Spin Qubits

We proposed and analyzed a technique to collectively enhance interactions between solid-state quantum registers composed from random networks of spin qubits. In such systems, disordered dipolar interactions generically result in localization. In our study, we demonstrated the emergence of a single collective delocalized eigenmode as one turned on a transverse field. The interaction strength between...
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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

Experimentally efficient methods for estimating the performance of quantum measurements

In this work we proposed metrics to characterize the performance of quantum measurements and provided experimentally accessible and efficient protocols to estimate these metrics. This work thus fills a gap in the characterization of quantum operations, which has until now focused on just the system evolution (via techniques such as quantum process tomography) providing a...
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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