Thu, January 1, 2009

A quantum gas microscope for detecting single atoms in a Hubbard-regime optical lattice

For the first time it was possible to observe single atoms in an optical lattice, where particles can tunnel from site to site.  An optical lattice is a crystals made of light that can be used to trap atoms at very low temperatures, creating a test bed for fundamental properties of crystalline materials. This research is part of a program on studying novel quantum matter using ultracold quantum gases. The work is led by Markus Greiner, Assistant Professor of Physics, principal investigator at Harvard and member at the NSF funded Harvard-MIT “Center for Ultracold Atoms”.

Thu, January 1, 2009

Demonstration of resolved sideband cavity cooling of a single ion

This is joint work with Vladan Vuletic.

Thu, January 1, 2009

Intense Atomic and Molecular Beams via Neon Buffer gas Cooling

D. Patterson, J. Rasmussen and J.M. Doyle, New Journal of Physics submitted (2009)

Thu, January 1, 2009

TOPS ?09

TOPS, acronym for Teaching Opportunities in the Physical Sciences, is a program to encourage physics majors to pursue careers in pre college science teaching. The 2009 season marked the seventh year that TOPS has been presented. Sponsored by CUA and NSF, TOPS brings eight undergraduate physics majors—juniors and sophomores from across the nation—to MIT for a six week teaching experience. TOPS participants live together as a group in MIT housing, along with a staff assistant from the former year. The participants work with three experienced high school physics teachers to prepare curricular material, design and practice classes, and then they move into the classroom to teach at the middle school and high school levels. The middle school experience takes place in a one-week class on heat, energy and optics at the Museum of Science, Boston.  The material is then revised and presented at the high school level in a two-week class held at MIT in the TOPS teaching workshop. The high school students come from the greater Boston community. The scientific themes of TOPS are seminal to the research program in CUA.  The PIs and graduate students make presentations on research work in progress and arrange laboratory visits, with the goal of enriching the TOPS experience as well and providing some unique teaching resources.  It appears that  about seventy percent of the TOPS participants go on to teaching careers, and in some cases the participants describe the TOPS experience as having been a decisive factor in their career decision. An article on the TOPS program appeared in Physics Today, October, 2009, p.  8.

Thu, January 1, 2009

Adiabatic Preparation of Many Body States in Optical Lattices

Thu, January 1, 2009

When one electron is not enough ….

Most research involving ultra-cold matter has been done with atoms with one active electron (i.e. an electron outside a closed shell of electrons).  New theoretical work by CUA researchers has demonstrated that atoms with two active electrons (the so called alkaline-earth atoms)

Thu, January 1, 2009

Coherence and Control of Quantum Registers based on Electronic Spin in a Nuclear Spin Bath

P. Cappellaro, L. Jiang, J. S. Hodges, and M. D. Lukin, Coherence and Control of Quantum Registers based on Electronic Spin in a Nuclear Spin Bath, Phys. Rev. Lett. 102, 210502

Thu, January 1, 2009

Microfabricated Cryogenic Ion Traps for Quantum Information Science

Thu, January 1, 2009

High-sensitivity diamond magnetometer with nanoscale resolution

J. M. Taylor, P. Cappellaro, L. Childress, L. Jiang, D. Budker, P. R. Hmmer, A. Yacoby, R. Walsworth, and M. D.Lukin, High-sensitivity diamond magnetometer with nanoscale resolution, Nature Physics 4, 810-816 (2008).

Thu, January 1, 2009

Swimming in the Fermi Sea

Our world is run by electrons. Whether we switch on a light, browse the internet or play music on the iPod, it is electrons moving through the wires, chips and headphones. But how do electrons actually get from A to B? After all, they have to get through a solid, a crystal maze of countless atoms. On their way through the solid, electrons push and pull nearby atoms around, attracting positive charges and repelling negative ones. It’s like an espalier, with arms flying high wherever the electron goes. These distortions in the crystal lattice thus closely follow the electron, and in fact the electron and the lattice deformations can be said to form a new entity or “quasi-particle”, called the polaron. Since the electron has to drag the lattice distortions with it, the polaron is heavier than an electron moving in empty space. That means a polaron is less inclined than a ‘bare’ electron to change its speed or direction of motion if someone pulls on it. Polarons are ubiquitous in solid state materials, they are crucial for the understanding of colossal magnetoresistance, and they are responsible for conduction in fullerenes and polymers.