Spin separation in cyclotron motion

TL;DR

This paper demonstrates how strong spin-orbit interaction in a 2D hole gas causes spin-dependent cyclotron orbits, enabling a tunable spin filter using magnetic focusing with two point contacts.

Contribution

It introduces a method to spatially separate spin states in a 2D hole gas via cyclotron motion, functioning as a tunable spin filter.

Findings

Spin-dependent cyclotron orbits observed in 2D hole gas

Two point contacts act as a tunable spin filter

Strong spin-orbit interaction causes different momenta for spin states

Abstract

Charged carriers with different spin states are spatially separated in a two-dimensional hole gas. Due to strong spin-orbit interaction holes at the Fermi energy have different momenta for two possible spin states travelling in the same direction and, correspondingly, different cyclotron orbits in a weak magnetic field. Two point contacts, acting as a monochromatic source of ballistic holes and a narrow detector in the magnetic focusing geometry are demonstrated to work as a tunable spin filter.