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Search Publications by: Ian Spielman (Fed)

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Displaying 151 - 175 of 206

Dynamically Slowed Collapse of a Bose-Einstein Condensate with Negative Scattering Length

December 3, 2012
Author(s)
Karina K. Jimenez Garcia, Robert L. Compton, Yu-Ju Lin, James V. Porto, Ian B. Spielman
We rapidly change the scattering length a_s of a ^{87}Rb Bose-Einstein condensate by means of a Feshbach resonance, simultaneously releasing the condensate from its harmonic trapping potential. When a_s is changed from positive to negative, the subsequent

Controlling Atomic Interactions with Light

December 1, 2012
Author(s)
Ross A. Williams, Lindsay J. LeBlanc, Karina K. Jimenez Garcia, Matthew C. Beeler, Abigail R. Perry, William D. Phillips, Ian B. Spielman
For the majority of the 20th century atomic physicists used light to probe and understand atoms. Today, scientists use light to manipulate particles with unprecedented levels of control, routinely cooling atoms to a few billionths of a degree above

Observation of a superfluid Hall effect

July 3, 2012
Author(s)
Lindsay J. LeBlanc, Karina K. Jimenez Garcia, Ross A. Williams, Matthew C. Beeler, Abigail R. Perry, William D. Phillips, Ian B. Spielman
Measurement techniques based upon the Hall effect are essential tools in condensed matter physics. Here, we report the first observation of a Hall effect in an ultracold gas of neutral atoms, revealed by measuring Bose-Einstein condensate's transport

Synthetic 3D Spin-Orbit Coupling

June 5, 2012
Author(s)
Ian B. Spielman, Brandon Anderson, Gediminas Juzeliunas, Victor Galitski
We describe a method for creating a three-dimensional analogue to Rashba spin-orbit coupling in systems of ultracold atoms. This laser induced coupling uses Raman transitions to link four internal atomic states with a tetrahedral geometry, and gives rise

The Peierls Substitution in an Engineered Lattice Potential

May 29, 2012
Author(s)
Karina K. Jimenez Garcia, Lindsay J. LeBlanc, Ross A. Williams, Matthew C. Beeler, Abigail R. Perry, Ian B. Spielman
Artificial gauge fields open new possibilities to realize quantum many-body systems with ultracold atoms, by constructing Hamiltonians usually associated with electronic systems. In the presence of a periodic potential, artificial gauge fields may bring

Formation of optical flux lattices for ultra cold atoms

May 24, 2012
Author(s)
Ian B. Spielman, Gediminas Juzeliunas
We explore the optical flux lattices produced for ultra-cold atoms in the radiation field when both the atom-light coupling and the detuning exhibit an oscillatory behavior. We analyze not only the magnetic flux but also the geometric vector potential

Beyond s-wave scattering for ultracold atoms

January 20, 2012
Author(s)
Ross A. Williams, Lindsay J. LeBlanc, Karina K. Jimenez Garcia, Matthew C. Beeler, Abigail R. Perry, William D. Phillips, Ian B. Spielman
Interactions between particles can be strongly altered by their environment. Here we demonstrate a technique for modifying interactions between ultracold atoms by dressing the bare atomic states with light, creating a screened interaction of vastly

Spin-Charge-Density Wave in a Squircle-Like Fermi Surface for Ultracold Atoms

January 20, 2012
Author(s)
Ian B. Spielman, Dima Makogon, Christiane de Morais Smith
We derive and discuss an experimentally realistic model describing ultracold atoms in an optical lattice including a commensurate, but staggered, Zeeman field. The resulting band structure is quite exotic; fermions in the third band have an unusual rounded

Chern Numbers Hiding in Time-of-Flight Images

December 21, 2011
Author(s)
Ian B. Spielman, Erhai Zhao, Noah Bray-Ali, Carl J. Williams, Indubala Satija
We present a novel technique for detecting topological invariants -- Chern numbers -- from time-of-flight images of ultra-cold neutral atoms. The Chern number of fermions in a lattice potential depends on magnetic field (for neutral atoms, generated by an

Viewpoint: Topological Invariants Made Manifest

November 28, 2011
Author(s)
Ian B. Spielman, Gediminas Juzeliunas
Topological order in some single particle cold atom systems can now be measured directly, instead of relying on proxies such as the quantized Hall conductance as is usually the case in conventional materials. This new measurement technique complements the

An optical lattice of flux

April 25, 2011
Author(s)
Ian B. Spielman
A suitable optical lattice for cold atoms could produce a large effective magnetic field in which the atoms would realize analogs to quantum Hall states.

Chiral Rashba Spin Textures in Ultra-Cold Fermi Gases

April 21, 2011
Author(s)
Ian B. Spielman, Jay Sau, Rajdeep Sensarma, Stephen Powell, Sankar Das Sarma
Spin-orbit coupling is an important ingredient in many recently discovered phenomena such as the spin-Hall effect and topological insulators. Of particular interest is topological superconductivity, with its potential application in topological quantum