Each dark core carries one turn of the condensate’s phase. Two repulsive paddles move through the field, shed vortices, and withdraw. The wave equation then decides what survives. Same-sign cores can organize into persistent groups; Instruments measures their circulation and organization.
“Negative temperature” refers to the statistical temperature of the vortex subsystem. This prototype does not estimate that temperature or establish thermodynamic equilibrium. The condensate is a two-dimensional mean-field model, with dimensionless lengths and time.
Sources and numerical notes
- Gauthier and collaborators, Giant vortex clusters in a two-dimensional quantum fluid. Preprint 2018; Science, 2019. The double-paddle protocol is the starting point for this smaller, smooth trap.
- Johnstone and collaborators, Order from chaos. Preprint 2018; Science, 2019. Signed nearest-neighbor correlations measure organization.
- Implementation, validation and measured limitations. The live solver uses a 512 by 512 grid and symmetric split-step Fourier evolution.