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Search Publications by: Ian Spielman (Fed)

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Displaying 51 - 75 of 102

Rashba realization: Raman with RF

May 2, 2016
Author(s)
Ian B. Spielman, Daniel Campbell
We theoretically explore a Rashba spin-orbit coupling scheme which operates entirely in the absolute ground state manifold of an alkali atom, thereby minimizing all inelastic processes. An energy gap between ground eigenstates of the proposed coupling can

Magnetic phases of spin-1 spin–orbit-coupled Bose gases

May 1, 2016
Author(s)
Ian B. Spielman, Daniel Campbell, Ryan Price, Ana Valdes-Curiel, Andika Putra, Dimitrius Trypogeorgos
Phases of matter are characterized by order parameters describing the type and degree of order in a system. Here we experimentally explore the magnetic phases present in a near-zero temperature spin-1 spin–orbit-coupled atomic Bose gas and the quantum

Spin-Orbit Coupled Bose-Einstein Condensates

April 15, 2016
Author(s)
Yu-Ju Lin, Karina K. Jimenez Garcia, Ian B. Spielman
Spin-orbit (SO) coupling -- the interaction between a quantum particle's spin and its momentum -- is ubiquitous in nature, from atoms to solids. In condensed matter systems, SO coupling is crucial for the spin-Hall effect and topological insulators; it

Quantum and Classical Dynamics of BEC in a Large-Period Optical Lattice

April 4, 2016
Author(s)
Ian B. Spielman, Johnny H. Huckans, Bruno Laburthe-Tolra, James V. Porto, William D. Phillips
We experimentally investigate diffraction of a ^u87 Rb Bose-Einstein Condensate from a 1D optical lattice. We use a range of lattice periods and timescales, including those beyond the Raman-Nath limit. We compare the results to quantum mechanical and

Direct observation of Feshbach enhanced s-wave scattering of fermions

December 17, 2015
Author(s)
Dina Genkina, Lauren M. Aycock, Hsin I Lu, Ian B. Spielman, Benjamin K. Stuhl
We directly measured the s-wave scattering cross-section of ultracold 40K atoms across the 20.2 mT Feshbach resonance by colliding pairs of degenerate Fermi gases (DFGs) and imaging the scattered atoms. Owing to DFG’s low density, few atoms scattered, even

Three-level Haldane-like model on a dice optical lattice

September 21, 2015
Author(s)
Ian B. Spielman, T. Andrijauskas, E. Anisimovas, M. Raciunas, A. Mekys, V. Kudriasov, G. Juzeliunas
We consider ultracold atoms in a two-dimensional optical lattice of the dice geometry in a tight-binding regime. The atoms experience a laser-assisted tunneling between the nearest neighbor sites of the dice lattice accompanied by the momentum recoil. This

Gauge matters: Observing the vortex-nucleation transition in a Bose condensate

June 18, 2015
Author(s)
Ian B. Spielman, LeBlanc Lindsey, Karina Jimenez-Garcia, Ross Williams, Matthew Beeler, William D. Phillips
The order parameter of a quantum-coherent many-body system includes one or more phase degrees of freedom, which, owing to the phase information's relationship to velocity, can be accessed using time-of-flight (TOF) imaging. Here, trapped Bose-Einstein

Assembling a complex quantum ensemble

April 10, 2015
Author(s)
Ian B. Spielman
Statistical mechanics provides a systematic approach for predicting the behavior of systems when only partial information is present. The key assumption underlying all of statistical mechanics is that every allowed configuration of the system, called a

Position-dependent spin-orbit coupling for ultracold atoms

February 18, 2015
Author(s)
Ian B. Spielman, Shih Wei Su, Shih-Chuan Gou, Ihe-Kau Liu, Luis Santos, Arturas Acus, Algirdas Mekys, Gediminas Juzeliunas
We theoretically explore atomic Bose-Einstein condensates (BECs) subject to position-dependent spin-orbit coupling (SOC). This SOC can be produced by cyclically Raman coupling four internal atomic ground (or metastable) states in an environment where the

Tunable Spin-Orbit Coupling via Strong Driving in Ultracold Atom Systems

December 12, 2014
Author(s)
Ian B. Spielman, Lindsay J. LeBlanc, Ross A. Williams, Matthew C. Beeler, Chunlei Qu, Ming Gong, Chuanwei Zhang
Spin-orbit coupling (SOC) is an essential ingredient in topological materials, conventional and quantum-gas based alike. Engineered spin-orbit coupling in ultracold atom systems unique in their experimental control and measurement opportunities provides a

Light Induced Gauge Fields for Ultracold Neutral Atoms

November 14, 2014
Author(s)
Ian B. Spielman
Ultracold neutral atoms, with their simple interactions along with well characterized, highly tunable system parameters, are an ideal platform for realizing and then quantitatively studying many-body phenomena. Many-body physics is perhaps most familiar in

A quenched spinor Bose-Einstein Condensate: From U(1) to U(1)xZ 2

March 25, 2014
Author(s)
Ian B. Spielman, Subhadeep De, Daniel Campbell, Ryan Price, Andika Putra, Brandon Anderson
We explore the time evolution of quasi-1D two component Bose-Einstein condensates (BEC's) following a quench from a spin polarized gas with a ${\rm U}(1)$ order parameter to a two component condensate with a ${\rm U}(1)\shorttimes{\rm Z}_2$ order parameter

Optimally Focused Cold Atom Systems Obtained Using Density-Density Correlations

January 23, 2014
Author(s)
Ian B. Spielman, Andika Putra, Daniel Campbell, Ryan Price, Subhadeep De
Resonant absorption imaging is a common technique for detecting the two-dimensional column density of ultracold atom systems. In many cases, the system’s thickness along the imaging direction greatly exceeds the imaging system’s depth of field, making the

The Mott Transition in a Bose Gas Measured Through Time of Flight

January 1, 2014
Author(s)
Ian B. Spielman, Karina Jimenez-Garcia
Ultracold atoms in optical lattices can realize nearly perfect analogs to condensed matter model systems without the complexity present in materials. In this chapter, we thoroughly describe our experimental characterization of the transition from

Magnetically generated spin-orbit coupling for ultracold atoms

September 18, 2013
Author(s)
Brandon M. Anderson, Ian B. Spielman, Gediminas Juzeliunas
We present a new technique for producing two and three dimensional Rashba-type spin-orbit coupling for ultra cold atoms without involving light. The method relies on a sequence of pulsed inhomogeneous magnetic fields imprinting suitable phase gradients on

A Raman-Induced Feshbach Resonance in a Single-Component Fermi Gas

August 26, 2013
Author(s)
Ian B. Spielman, Ross Williams, Matthew Beeler, Lindsay J. LeBlanc, Karina Jimenez-Garcia
Ultracold gases of interacting spin-orbit coupled fermions are predicted to display exotic phenom- ena such as topological superfluidity and its associated Majorana fermions. Here, we experimentally demonstrate a route to strongly-interacting single

Direct Observation of Zitterbewegung in a Bose-Einstein condensate

July 3, 2013
Author(s)
Lindsay J. LeBlanc, Matthew Beeler, Karina Jimenez-Garcia, Abigail R. Perry, Seiji Sugawa, Ross Williams, Ian B. Spielman
Zitterbewegung, a force-free trembling motion first predicted for relativistic fermions like electrons, was an unexpected consequence of the Dirac equation's unification of quantum mechanics and special relativity. Though the oscillatory motion's large

Detection of Topological Matter with Quantum Gases

June 20, 2013
Author(s)
Ian B. Spielman
Creating and measuring topological matter – with order deeply imbedded it’s quantum mechanical eigenstates structure – presents unique experimental challenges. This sort of intrinsically non-local order might seem experimentally inaccessible in any

Fermion Mediated Interactions Between Ultracold Bosons

June 16, 2013
Author(s)
Ian B. Spielman, Subhadeep De
We describe a new method for creating spin-dependent long-range interactions between atomic ultra-cold neutral bosons in an optical lattice. In this proposal, the bosonic system is immersed in a spin polarized degenerate Fermi gas. We first show that the

The Spin Hall Effect in a Quantum Gas

June 13, 2013
Author(s)
Matthew C. Beeler, Ross A. Williams, Karina K. Jimenez Garcia, Lindsay J. LeBlanc, Abigail R. Perry, Ian B. Spielman
Electronic properties like current flow are usually unaffected by the electron’s spin angular momentum, an internal degree of freedom present in quantum particles that can usually be either “up” or “down”. The spin-Hall effects (SHEs), first proposed 40

Direct Imaging of Topological Edges States with Cold Atoms

March 7, 2013
Author(s)
Ian B. Spielman, Nathan Goldman, Jean Dalibard, Alexandre Dauphin, Maciej Lewenstein, Fabrice Gerbier, Peter Zoller
Detecting manifestation of topological order in cold-atom experiments is an outstanding challenge, the resolution of which offers novel perspectives on topological phases of matter. In material systems, unambiguous signatures of topological states have

Flux Lattices Reformulated

December 12, 2012
Author(s)
Ian B. Spielman, Gediminas Juzeliunas
We theoretically explore the optical flux lattices produced for ultra-cold atoms subject to laser fields where both the atom-light coupling and the effective detuning are spatially periodic. We analyze the geometric vector potential and the magnetic flux

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