Selective Population of Edge States in a 2D Topological Band System

TL;DR

This paper investigates how quenching the quadratic Zeeman field in a 2D topological band system of spin-one atoms induces edge state instabilities, leading to controllable spin currents along the system's boundary.

Contribution

It demonstrates that quenching can selectively populate edge modes in a 2D topological system with spin-one atoms, revealing new dynamical control mechanisms.

Findings

Edge modes become dynamically unstable after quenching.

Spin currents grow exponentially along the boundary.

Selective population of edge modes is achievable via quench tuning.

Abstract

We consider a system of interacting spin-one atoms in a hexagonal lattice under the presence of a synthetic gauge field. Quenching the quadratic Zeeman field is shown to lead to a dynamical instability of the edge modes. This, in turn, leads to a spin current along the boundary of the system which grows exponentially fast in time following the quench. Tuning the magnitude of the quench can be used to selectively populate edge modes of different momenta. Implications of the intrinsic symmetries of Hamiltonian on the dynamics are discussed. The results hold for atoms with both antiferromagnetic and ferromagnetic interactions.