181 citations · 1k across the 16 of their papers we have counts for
16 papers
Connecting shear-flow and vortex array instabilities in annular atomic superfluids
D. Hernandez-Rajkov, N. Grani, F. Scazza +8
At the interface between two fluid layers in relative motion, infinitesimal fluctuations can be exponentially amplified, inducing vorticity and the breakdown of the laminar flow. T…
Sound emission and annihilations in a programmable quantum vortex collider
W. J. Kwon, G. Del Pace, K. Xhani +5
In quantum fluids, the quantisation of circulation forbids the diffusion of a vortex swirling flow seen in classical viscous fluids. Yet, a quantum vortex accelerating in a superfl…
An efficient high-current circuit for fast radio-frequency spectroscopy in cold atomic gases
F. Scazza, G. Del Pace, L. Pieri +3
We design and implement a low-impedance, high-current radio-frequency (RF) circuit, enabling fast coherent coupling between magnetic levels in cold alkali atomic samples. It is bas…
Strongly correlated superfluid order parameters from dc Josephson supercurrents
W. J. Kwon, G. Del Pace, R. Panza +5
The dc Josephson effect provides a powerful phase-sensitive tool for investigating superfluid order parameters. We report on the observation of dc Josephson supercurrents in strong…
Observation of von Kármán Vortex Street in an Atomic Superfluid Gas
Woo Jin Kwon, Joon Hyun Kim, Sang Won Seo +1
We report on the experimental observation of vortex cluster shedding from a moving obstacle in an oblate atomic Bose-Einstein condensate. At low obstacle velocities above a cri…
Role of thermal friction in relaxation of turbulent Bose-Einstein condensates
Joon Hyun Kim, Woo Jin Kwon, Yong-il Shin
In recent experiments, the relaxation dynamics of highly oblate, turbulent Bose-Einstein condensates (BECs) was investigated by measuring the vortex decay rates in various sample c…
Collisional Dynamics of Half-Quantum Vortices in a Spinor Bose-Einstein Condensate
Sang Won Seo, Woo Jin Kwon, Seji Kang +1
We present an experimental study on the interaction and dynamics of half-quantum vortices (HQVs) in an antiferromagnetic spinor Bose-Einstein condensate. By exploiting the orbit mo…
Thermal friction on quantum vortices in a Bose-Einstein condensate
Geol Moon, Woo Jin Kwon, Hyunjik Lee +1
We investigate the dissipative dynamics of a corotating vortex pair in a highly oblate axisymmetric Bose-Einstein condensate trapped in a harmonic potential. The initial vortex sta…
Periodic shedding of vortex dipoles from a moving penetrable obstacle in a Bose-Einstein condensate
Woo Jin Kwon, Sang Won Seo, Yong-il Shin
We investigate vortex shedding from a moving penetrable obstacle in a highly oblate Bose-Einstein condensate. The penetrable obstacle is formed by a repulsive Gaussian laser beam t…
Half-Quantum Vortices in an Antiferromagnetic Spinor Bose-Einstein Condensate
Sang Won Seo, Seji Kang, Woo Jin Kwon +1
We report on the observation of half-quantum vortices (HQVs) in the easy-plane polar phase of an antiferromagnetic spinor Bose-Einstein condensate. Using in situ magnetization-sens…
Critical Velocity for Vortex Shedding in a Bose-Einstein Condensate
Woo Jin Kwon, Geol Moon, Sang Won Seo +1
We present measurements of the critical velocity for vortex shedding in a highly oblate Bose-Einstein condensate with a moving repulsive Gaussian laser beam. As a function of the b…
Rotating a Bose-Einstein condensate by shaking an anharmonic axisymmetric magnetic potential
Seji Kang, J. Choi, S. W. Seo +2
We present an experimental method for rotating a Bose-Einstein condensate trapped in an axisymmetric magnetic potential. This method is based on the anharmonicity of the trapping p…
Relaxation of superfluid turbulence in highly oblate Bose-Einstein condensates
Woo Jin Kwon, Geol Moon, Jae-yoon Choi +2
We investigate thermal relaxation of superfluid turbulence in a highly oblate Bose-Einstein condensate. We generate turbulent flow in the condensate by sweeping the center region o…
Observation of a Geometric Hall Effect in a Spinor Bose-Einstein Condensate with a Skyrmion Spin Texture
Jae-yoon Choi, Seji Kang, Sang Won Seo +2
For a spin-carrying particle moving in a spatially varying magnetic field, effective electromagnetic forces can arise due to the geometric phase associated with adiabatic spin rota…
Probing Phase Fluctuations in a 2D Degenerate Bose Gas by Free Expansion
Jae-yoon Choi, Sang Won Seo, Woo Jin Kwon +1
We measure the power spectrum of the density distribution of a freely expanding 2D degenerate Bose gas, where irregular density modulations gradually develop due to the initial pha…
Observation of Topologically Stable 2D Skyrmions in an Antiferromagnetic Spinor Bose-Einstein Condensate
Jae-yoon Choi, Woo Jin Kwon, Yong-il Shin
We present the creation and time evolution of two-dimensional Skyrmion excitations in an antiferromagnetic spinor Bose-Einstein condensate. Using a spin rotation method, the Skyrmi…