Pulsed-gate spectroscopy of single-electron spin states in bilayer graphene quantum dots

TL;DR

This study demonstrates pulsed-gate spectroscopy on bilayer graphene quantum dots, revealing a lower bound of 0.5 microseconds for spin relaxation time, advancing the understanding of spin coherence for quantum computing applications.

Contribution

It introduces a novel pulsed-gate spectroscopy method to measure spin relaxation times in bilayer graphene quantum dots, a previously unexplored area.

Findings

Spin relaxation time lower bound of 0.5 microseconds

Successful transport measurement through a high-frequency gate controlled quantum dot

First extraction of spin relaxation dynamics in bilayer graphene quantum dots

Abstract

Graphene and bilayer graphene quantum dots are promising hosts for spin qubits with long coherence times. Although recent technological improvements make it possible to confine single electrons electrostatically in bilayer graphene quantum dots, and their spin and valley texture of the single particle spectrum has been studied in detail, their relaxation dynamics remains still unexplored. Here, we report on transport through a high-frequency gate controlled single-electron bilayer graphene quantum dot. By transient current spectroscopy of single-electron spin states, we extract a lower bound of the spin relaxation time of 0.5~$\mu$s. This result represents an important step towards the investigation of spin coherence times in graphene-based quantum dots and the implementation of spin-qubits.