News: Research Highlights

260 articles

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...

News type: 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.

News type: 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...

News type: 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...

News type: 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...

News type: 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...

News type: Research Highlights

Tue, January 1, 2013

Dressed-State Resonant Coupling between Bright and Dark Spins in Diamond

A critical ingredient for quantum control of atom-like and hybrid systems is a better understanding of decoherence as well as the control of many-body quantum dynamics.

News type: 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...

News type: Research Highlights

Tue, January 1, 2013

Pauli Paramagnetism of an Ideal Fermi Gas

Using the two lowest hyperfine states of a non-interacting ultracold Fermi gas of 6Li as pseudospin states, we have measured the magnetic susceptibility of such a system as a demonstration of the textbook physics of Pauli paramagnetism [1]. An imbalanced spin mixture of 6Li is trapped in the harmonic confinement potential at the focus of...

News type: 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...

News type: Research Highlights