Landau-Zener-Stuckelberg-Majorana interferometry of a single hole

TL;DR

This study explores Landau-Zener-Stuckelberg-Majorana interferometry in a single hole system with strong spin-orbit interaction, revealing complex tunneling pathways and potential for all-electrical spin manipulation.

Contribution

It demonstrates the first detailed LZSM spectroscopy of a single hole with strong SOI, uncovering new spin-flipping tunneling channels and interference patterns.

Findings

Observation of photon-assisted tunneling at B=0

Identification of spin-flipping tunneling channels due to SOI

Potential for all-electrical hole spin manipulation

Abstract

We perform Landau-Zener-Stuckelberg-Majorana (LZSM) spectroscopy on a system with strong spin-orbit interaction (SOI), realized as a single hole confined in a gated double quantum dot. In analogy to the electron systems, at magnetic field B=0 and high modulation frequencies we observe the photon-assisted tunneling (PAT) between dots, which smoothly evolves into the typical LZSM funnel-shaped interference pattern as the frequency is decreased. In contrast to electrons, the SOI enables an additional, efficient spin-flipping interdot tunneling channel, introducing a distinct interference pattern at finite B. Magneto-transport spectra at low-frequency LZSM driving show the two channels to be equally coherent. High-frequency LZSM driving reveals complex photon-assisted tunneling pathways, both spin-conserving and spin-flipping, which form closed loops at critical magnetic fields. In one such loop an arbitrary hole spin state is inverted, opening the way toward its all-electrical manipulation.