Programme

I.4 -- Invited, VCTP-49

Date: Tuesday, 30 July 2024

Time: 16:00 - 16:40

Online presentation

Exploring Chiral Spin States in Curved Spaces: Insights from Ring Geometries

Dario Bercioux

Donostia International Physics Center, Spain

In this presentation, I will review the problem of electron spins moving in curved spaces, focusing on the problem of ring geometry. I will then demonstrate how chiral states in circular graphene pn junctions, subjected to normal magnetic fields and strong proximitized spin-orbit coupling, can imitate those of propagating spin carriers in semiconducting quantum rings. I will derive the effective one-dimensional Hamiltonian governing the zero modes' spin dynamics and calculate the geometric phase. I will also show that for a given polarity of the junction, a special point exists in parameter space where the spin is completely polarized along the radial direction in the graphene plane. Additionally, I will propose a novel quantum-Hall interferometer setup that can readily identify and observe these remarkable features. By employing this interferometer, I can gain valuable insights into the intricate nature of chiral spin states and their manifestation in ring geometries. Ref. D. Bercioux, D. Frustaglia & A. De Martino, Phys. Rev B 108, 225140 (2023) (on-line presentation)

Presenter: Dario Bercioux