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Search Publications by: Ian Spielman ()

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Displaying 76 - 100 of 103

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

A Route to Quantum Magnetism

April 13, 2011
Author(s)
Ian B. Spielman
The trend in using ultracold atoms as simulators of condensed-matter and many-body phenomena is gaining momentum. These systems can now be used to simulate quantum magnetism.

Synthetic Electric and Magnetic Fields for Ultracold Neutral Atoms

January 1, 2011
Author(s)
William D. Phillips, Yu-Ju Lin, Robert L. Compton, Karina K. Jimenez Garcia, Abigail R. Perry, James V. Porto, Ian B. Spielman
We use Raman coupling between magnetic sublevels of a 87Rb Bose-Einstein condensate (BEC) to create an effective vector gauge field for the neutral atoms. They behave as if they were charged particles in a magnetic vector potential. With appropriate

Engineering Time-Reversal Invariant Topological Insulators With Ultra-Cold Atoms

December 16, 2010
Author(s)
Ian B. Spielman, Nathan Goldman, Indubala I. Satija, Predrag Nikolic, Alejandro Bermudez, Miguel A. Martin-Delgado, Maciej Lewenstein
Topological insulators are a broad class of unconventional states that respect all symmetries of the system, but have non-trivial transport and topological properties which cannot be defined locally. Until recently, all known realizations of these phases

Phases of a 2D Bose Gas in an Optical Lattice

September 9, 2010
Author(s)
Karina K. Jimenez Garcia, Yu-Ju Lin, James V. Porto, Ian B. Spielman
Ultra-cold atoms in optical lattices realize essential models in condensed matter physics. Like with most experiments with ultra-cold atoms, our Rubidium-87 Bose Einstein condensate is confined in a harmonic trapping potential that persists even when

Synthetic Magnetic Fields for Ultracold Neutral Atoms

December 3, 2009
Author(s)
Yu-Ju Lin, Robert L. Compton, Karina K. Jimenez Garcia, James V. Porto, Ian B. Spielman
Neutral atomic Bose condensates and degenerate Fermi gases have realized important many-body phenomena in their most simple and essential forms, without many of the complexities usually associated with material systems. A rich source of physics in

Rapid Production of ^87^Rb BECs in a Combined Magnetic and Optical Potential

August 31, 2009
Author(s)
Yu-Ju Lin, Abigail R. Perry, Robert L. Compton, Ian B. Spielman, James V. Porto
We describe an apparatus for quickly and simply producing ^87^Rb Bose-Einstein condensates. It is based on a magnetic quadrupole trap and a red detuned optical dipole trap. We collect atoms in a magneto-optical trap (MOT) and then capture the atom in a

Optical Lattice-Based Addressing and Control of Long-Lived Neutral-Atom Qubits

July 6, 2009
Author(s)
Nathan Lundblad, J Obrecht, Ian B. Spielman, James V. Porto
The establishment of a scalable, addressable, and long-lived scheme for quantum computing would be a scientific watershed, harnessing the laws of quantum physics to solve classically intractable problems. Many proposed computational platforms are driven by

Raman Processes and Effective Gauge Potentials

June 19, 2009
Author(s)
Ian B. Spielman
Here I discuss a new technique by which light-induced gauge potentials allow systems of ultra-cold neutral atoms to behave like charged particles in a magnetic field. Here, atoms move in a uniform laser field with a spatially varying Zeeman shift and

A Bose-Einstein Condensate in a Uniform Light-Induced Vector Potential

March 30, 2009
Author(s)
Yu-Ju Lin, Robert L. Compton, Abigail R. Perry, William D. Phillips, James V. Porto, Ian B. Spielman
We use a two-photon dressing field to create an effective vector gauge potential for Bose-condensed ^87Rb atoms in the F=1 hyperfine ground state. The dressed states in this Raman field are spin and momentum superpositions, and we adiabatically load the

Atoms in a Radio-Frequency-Dressed Optical Lattice

April 18, 2008
Author(s)
Ian B. Spielman, James V. Porto, William D. Phillips, Ben Brown, Patricia Lee, Nathan Lundblad
We load cold atoms into an optical lattice dramatically reshaped by radio-frequency coupling of statedependent lattice potentials. This radio-frequency dressing changes the unit cell of the lattice at a subwavelength scale, such that its curvature and