Topological superfluid defects with discrete point group symmetries

Abstract

Discrete symmetries are spatially ubiquitous but are often hidden in internal states of systems where they can have especially profound consequences. In this work we create and verify exotic magnetic phases of atomic spinor Bose–Einstein condensates that, despite their continuous character and intrinsic spatial isotropy, exhibit complex discrete polytope symmetries in their topological defects. Using carefully tailored spinor rotations and microwave transitions, we engineer singular line defects whose quantization conditions, exchange statistics, and dynamics are fundamentally determined by these underlying symmetries. We show how filling the vortex line singularities with atoms in a variety of different phases leads to core structures that possess magnetic interfaces with rich combinations of discrete and continuous symmetries. Such defects, with their non-commutative properties, could provide unconventional realizations of quantum information and interferometry.

Topological atom optics and beyond with knotted quantum wavefunctions

“…Spin-1 wavefunction combines a discrete two-fold symmetry with a condensate phase, resulting in the polar order-parameter symmetry of the unoriented axis and the 2π phase. Discrete polytope symmetries can be found in higher-spin systems that support more complex topological structures, as experimentally illustrated for vortex creation 53 .…”