26th Australian Institute of Physics Congress and the Australian and New Zealand Conference on Optics and Photonics

Experimental Creation of Novel Solitons Structures in Multicomponent Bose-Einstein Condensates

Not scheduled

20m

Belinda Hutchinson Building (The University of Sydney )

Contributed Oral AIP | Atomic and Molecular Physics (ATMOP)

Description

Solitons—self-reinforcing wave packets that propagate without dispersing—occupy a distinctive place in physics because they arise from a delicate balance between nonlinearity and dispersion, allowing them to behave like stable, particle-like excitations even as they carry topological or phase information through a medium. First identified in shallow water waves and later found in optical fibers, plasmas, and superfluids, solitons have become a unifying concept linking nonlinear wave dynamics across disciplines. In quantum gases, spinor Bose-Einstein condensates (sBECs) provide a particularly rich platform for studying solitons, since their multicomponent order parameter supports topological defects—such as flow-defect solitons (FDSs)—that have no analogue in scalar systems and offer insight into fundamental questions of symmetry breaking, superfluid dynamics, and defect formation.
This chapter demonstrates novel techniques for creating topological defects in the easy-plane phase (EPP) of an sBEC. We develop the theory of phase imprinting using magic-wavelength light in the EPP, showing that the transverse spin angle can be spatially sculpted to generate FDSs in one and two dimensions. We then introduce a calibration method that measures the imprinted spin angle by treating the DMD-sculpted light as an effective fictitious magnetic field, precisely characterized via a Ramsey sequence. Using this protocol, we imprint a type-I FDS and verify it by comparing the measured transverse spin profile to theoretical predictions. We further propose a novel scheme for creating a type-II FDS using localized microwave pulses that advance half the m_F = 0 condensate by π, seeding its formation.
A numerical toolkit for solving the three-component Gross-Pitaevskii equation governing sBECs is presented and benchmarked against theory, including ground-state evolution in a 1D box trap. We simulate both FDS types beyond the exactly solvable regime, finding excellent agreement with theoretical predictions, and propose an experimentally feasible soliton collider to probe their collision dynamics.