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Search Publications by: Ian Spielman (Fed)

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Displaying 1 - 25 of 102

Observation of anisotropic superfluid density in an artificial crystal

October 18, 2023
Author(s)
Ian Spielman, Mingshu Zhao, Junhent Tao
We experimentally and theoretically investigate the anisotropic speed of sound of an atomic superfluid (SF) Bose-Einstein condensate in a 1D optical lattice. Because the speed of sound derives from the superfluid density, implying that this density is

Weak-Measurement-Induced Heating in Bose-Einstein Condensates

June 23, 2023
Author(s)
Emine Altuntas, Ian Spielman
Ultracold atoms are an ideal platform for understanding system-reservoir dynamics of many-body systems. Here, we study quantum back-action in atomic Bose-Einstein condensates, weakly interacting with a far-from resonant, i.e., dispersively interacting

Feedback cooled Bose-Einstein condensation: near and far from equilibrium

June 13, 2023
Author(s)
Ian Spielman, Hilary Hurst, Evan Yamaguchi
Continuously measured interacting quantum systems almost invariably heat, causing loss of quantum coherence. Here we study Bose-Einstein condensates (BECs) subject to repeated weak measurement of the atomic density and describe several protocols for

An ultra-low noise bipolar current source

June 6, 2023
Author(s)
Ian Spielman, Alessandro Restelli, Mingshu Zhao, Junheng Tao, Qiyu Liang
The precise control of dc magnetic fields is crucial in wide range of experimental platforms, from ultracold quantum gases, nuclear magnetic resonance, to precision measurements. In each of these cases the Zeeman effect causes quantum states to shift in

Quantum back-action limits in dispersively measured Bose-Einstein condensates

April 8, 2023
Author(s)
Ian Spielman, Emine Altuntas
A fundamental tenet of quantum mechanics is that measurements change a system's wavefunction to that most consistent with the measurement outcome, even if no observer is present. Weak measurements produce only limited information about the system, and as a

Interference induced anisotropy in a two-dimensional dark state optical lattice

March 27, 2023
Author(s)
Ian Spielman, Gediminas Juzeliunas, Edvinas Gvozdiovas
We describe a two-dimensional optical lattice for ultracold atoms with spatial structure below the diffraction limit created by a bichromatic optical standing wave. At every point in space these fields couple the internal atomic states in a three-level

Topological charge pumping with subwavelength Raman lattices

February 15, 2023
Author(s)
Ian Spielman, Gediminas Juzeliunas, Domantas Burba, mantas Raciunas
Recent experiments demonstrated deeply subwavelength lattices using atoms with $N$ internal states Raman-coupled with lasers of wavelength $\lambda$. The resulting unit cell was $\lambda/2N$ in extent, an $N$-fold reduction compared to the usual $\lambda/2

Dark solitons in Bose-Einstein condensates: a dataset for many-body physics research

December 21, 2022
Author(s)
Amilson R. Fritsch, Shangjie Guo, Sophia Koh, Ian Spielman, Justyna Zwolak
We establish a dataset of over 1.6 x 10^4 experimental images of Bose–Einstein condensates containing solitonic excitations to enable machine learning (ML) for many-body physics research. About 33 % of this dataset has manually assigned and carefully

Dynamical Instability of 3d Stationary and Traveling Planar Dark Solitons

November 9, 2022
Author(s)
Ian Spielman, Amilson R. Fritsch, T. Mithun, Panayotis Kevrekidis
Here we revisit the topic of stationary and propagating solitonic excitations in self-repulsive three-dimensional Bose-Einstein condensates by quantitatively comparing theoretical analysis and associated numerical computations with our experimental results

Floquet engineering topological Dirac bands

July 22, 2022
Author(s)
Ian Spielman, Mingwu Lu, Amilson R. Fritsch, Graham Reid, Alina Pineiro Escalera
We experimentally realized a time-periodically modulated 1D lattice for ultracold atoms featuring a pair of linear bands, each associated with a Floquet winding number: a topological invariant. These bands are spin-momentum locked and almost perfectly

Accurate Determination of Hubble Attenuation and Amplification in Expanding and Contracting Cold-Atom Universes

February 28, 2022
Author(s)
Swarnav Banik, Monica Gutierrez Galan, Hector Sosa Martinez, 1, Madison Anderson, Stephen Eckel, Ian Spielman, Gretchen K. Campbell
In the expanding universe, relativistic scalar fields are thought to be attenuated by "Hubble friction," which results from the dilation of the underlying spacetime metric. By contrast, in a contracting universe this pseudofriction would lead to

Wilson loop and Wilczek-Zee phase from a non-Abelian gauge field

September 30, 2021
Author(s)
Ian Spielman, Francisco Salces Carcoba, Andika Putra, Yuchen Yue, Seiji Sugawa
Quantum states can acquire a geometric phase called the Berry phase after adiabatically traversing a closed loop, which depends on the path not the rate of motion. The Berry phase is analogous to the Aharonov–Bohm phase derived from the electromagnetic

Machine-learning enhanced dark soliton detection in Bose-Einstein condensates

June 15, 2021
Author(s)
Shangjie Guo, Amilson R. Fritsch, Ian Spielman, Justyna Zwolak
Most data in cold-atom experiments comes from images, the analysis of which is limited by our preconceptions of the patterns that could be present in the data. We focus on the well-defined case of detecting dark solitons—appearing as local density

Coherence and decoherence in the Harper-Hofstadter model

May 19, 2021
Author(s)
Ian Spielman, Qiyu Liang, Dimi Trypogeorgos, Ana Valdes-Curiel, Junheng Tao, Mingshu Zhao
We quantum simulated the 2D Harper-Hofstadter (HH) lattice model in a highly elongated tube geometry—three sites in circumference—using an atomic Bose-Einstein condensate. In addition to the usual transverse (out-of-plane) magnetic flux, piercing the

Multiple-camera defocus imaging of ultracold atomic gases

May 13, 2021
Author(s)
Ian Spielman, Francisco Salces Carcoba, Yuchen Yue, Seiji Sugawa, Abigail Perry
In cold atom experiments, each image of light refracted and absorbed by an atomic ensemble carries a remarkable amount of information. Numerous imaging techniques including absorption, fluorescence, and phase-contrast are commonly used. Other techniques

Feedback Induced Magnetic Phases in Binary Bose-Einstein Condensates

December 7, 2020
Author(s)
Ian B. Spielman, Shangjie Guo, Hilary M. Hurst
Weak measurement in tandem with real-time feedback control is a new route toward engineering novel non-equilibrium quantum matter. Here we develop a theoretical toolbox for quantum feedback control of multicomponent Bose-Einstein condensates (BECs) using

Enhanced transport of spin-orbit coupled Bose gases in disordered potentials

September 17, 2020
Author(s)
Yuchen Yue, Ian Spielman, Carlos S? de Melo
Anderson localization is single particle localization phenomena in disordered media that is accompanied by an absence of diffusion. Spin-orbit coupling (SOC) describes an interaction between a particle's spin and its momentum that directly affects its

Creating solitonic excitations with controllable velocity in Bose-Einstein condensates

May 20, 2020
Author(s)
Amilson R. Fritsch, Mingwu Lu, Alina M. Pineiro Escalera, Graham H. Reid, Ian Spielman
Established techniques for deterministically creating dark solitons in repulsively interacting atomic Bose-Einstein condensates (BECs) can only access a narrow range of soliton velocities. Because velocity a ects the stability of individual solitons and

Realization of a deeply subwavelength adiabatic optical lattice

February 12, 2020
Author(s)
Ian B. Spielman, Ana Valdes Curiel, Russell P. Anderson, T. Andrijauskas, Gediminas Juzeliunas, Qiyu Liang, Junheng Tau, Dimitrius Trypogeorgos, Mingshu Zhao
We propose and realize a deeply sub-wavelength optical lattice for ultracold neutral atoms using $N$ resonantly Raman-coupled internal degrees of freedom. Although counter-propagating lasers with wavelength $\lambda$ provided two-photon Raman coupling, the

Repeated Measurements with Minimally Destructive Partial-Transfer Absorption Imaging

December 2, 2019
Author(s)
Ian B. Spielman, Ana Valdes Curiel, Dimitris Trypogeorgos, Erin Marshall, Nathan Lundblad
We demonstrate partial-transfer absorption imaging as a technique for repeatedly imaging an ultracold atomic ensemble with minimal perturbation. We prepare an atomic cloud in a state that is dark to the imaging light and then use a microwave pulse to

Exceeding the Sauter-Schwinger limit of pair production with a quantum gas

September 21, 2019
Author(s)
Alina M. Pineiro Escalera, Mingwu Lu, Dina Genkina, Ian Spielman
We quantum-simulated particle-antiparticle pair production with a bosonic quantum gas in an optical lattice by emulating the requisite 1d Dirac equation and uniform electric field. We emulated field strengths far in excess of Sauter-Schwinger's limit for