Fig. 2: Phase delay control of vortex lines.
From: Coupled quantum vortex kinematics and Berry curvature in real space
a Polariton amplitude maps in the phase delay experiment. The snapshots are taken at t = 3.7 ps, with four different phase delays φAB spaced by π/4. The phase singularities have been marked with blue/red dots in the amplitude maps, and the black/white line is the circle fitting their positions. b The specific xyt vortex lines (at a given phase delay) of the two unitary vortices (blue and red tubes) during one and half Rabi-oscillations period (time range t = 2.5–3.7 ps). The topological bottle surface described by the vortex cores when sweeping the optical phase delay between the two pulses has been mapped (by spheres) at 100 fs or 50 fs time intervals, spanning φAB in a 15π range by successive λ/8 steps. c Blue points represent the positions of photonic vortex cores in real space at fixed times, when scanning the phase delay as in (b). At the times when the photon vortex cores are more distant from the center (e.g., t = 3.0 ps), the phase scan makes their positions rotate with central symmetry, overlapping the fitting circle (black solid line). When the cores are closer to the center (e.g., t = 2.6 and 3.4 ps), the phase scan makes them describe two ellipses not overlapping anymore with the fitting circle, but composing a 8-shaped line.
