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Joined 2026-09-21 Message
Baptiste Battelier Created 2026-10-18 Updated 2026-11-05
An experimental atomic physicist who coauthored a study of the Berezinskii–Kosterlitz–Thouless transition in a trapped gas. Interference of planar atomic clouds probed spatial coherence, connecting a low-dimensional many-particle state to a directly visible optical image.[ref]
Marc Cheneau Created 2026-10-18 Updated 2026-11-05
An experimental physicist who coauthored measurements of low-dimensional coherence in ultracold gases. The experiment used interference of two planar clouds to study the crossover associated with the Berezinskii–Kosterlitz–Thouless transition, linking spatial correlations to observable fringe structure.[ref]
Peter Krüger Created 2026-10-18 Updated 2026-11-05
An experimental atomic physicist who coauthored a test of the Berezinskii–Kosterlitz–Thouless transition in trapped ultracold gases. Interference measurements examined how coherence changes with temperature, giving a laboratory probe of ordering that differs from conventional three-dimensional Bose-Einstein condensation.[ref]
Berezinskii-Kosterlitz-Thouless Crossover in a Trapped Atomic Gas by Zoran Hadzibabic and others. Coherence measurements and low-dimensional crossover
In 2006, Zoran Hadzibabic, Peter Krüger, Marc Cheneau, Baptiste Battelier and Jean Dalibard split a cooled rubidium-87 cloud into two independent planar gases using an optical lattice. After release, the expanding sheets overlapped; absorption imaging recorded their matter-wave interference. Smooth fringe waviness revealed thermal phase fluctuations, while sharp dislocations indicated isolated vortices. The initial evaporative-cooling endpoint controlled the preparation; central fringe contrast served as a degeneracy proxy because direct thermometry in the lattice was difficult.[ref]
Berezinskii-Kosterlitz-Thouless Crossover in a Trapped Atomic Gas by Zoran Hadzibabic and others. Pages 1–2, preparation and readout; Fig. 1; temperature control and Fig. 2
Loss of extended coherence coincided with increased vortex signatures. The optical trap and finite cloud produced a crossover; tightly bound pairs were unresolved, and short-wavelength modes could contaminate high-temperature counts. These were observations of the vortex-unbinding mechanism, not a direct measurement of phase stiffness or a sharp homogeneous universal stiffness jump. The authors left the sample's superfluidity open.[ref]
Berezinskii-Kosterlitz-Thouless Crossover in a Trapped Atomic Gas by Zoran Hadzibabic and others. Pages 3–4, Figs. 3–4; geometry, invisible pairs, detection limits and final paragraph on unmeasured superfluidity
Zoran Hadzibabic Created 2026-10-18 Updated 2026-11-05
An experimental atomic physicist who coauthored a trapped-gas study of the Berezinskii–Kosterlitz–Thouless transition. Its interference measurements connected the loss of long-distance coherence with vortex physics, showing how a carefully confined gas can test ideas about two-dimensional ordering.[ref]