From the topological spin-Hall effect to the non-Hermitian skin effect in an elliptical micropillar chain

• Main Authors: Mandal, Subhaskar, Banerjee, Rimi, Liew, Timothy Chi Hin
• Other Authors: School of Physical and Mathematical Sciences
• Format: Article
• Language: English
• Published: 2023
• Subjects: Science::Physics; Topological Spin-Hall Effect; Non-Hermitian Skin Effect
• Online Access: https://hdl.handle.net/10356/164435
• Institution: Nanyang Technological University

The topological spin-Hall effect causes different spins to propagate in opposite directions based on Hermitian physics. The non-Hermitian skin effect causes the localization of a large number of modes of a system at its edges. Here we propose a system based on exciton-polariton elliptical micropillars hosting both the effects. The polarization splitting of the elliptical micropillars gives rise to the topological spin-Hall effect in a one dimensional lattice. When a circularly polarized external incoherent laser is used to imbalance effective decay rates of the different spin polarizations, the system transits to a non-Hermitian regime showing the skin effect. These effects have implications for robust polariton transport as well as the deterministic formation of multiply charged vortices and persistent currents.