Coplanar stripline antenna design for optically detected magnetic resonance on semiconductor quantum dots

TL;DR

This paper presents a coplanar stripline antenna design that enables coherent control of electron spins in semiconductor quantum dots, integrating microwave delivery, electrical gating, and masking in a single structure.

Contribution

The paper introduces a multifunctional coplanar stripline antenna optimized for quantum dot spin control, combining design, testing, and simulation to meet experimental requirements.

Findings

Achieved electrically detected magnetic resonance with the antenna.

Estimated magnetic field of ~0.2mT at quantum dot location.

Pi-pulse time of ~0.3 microseconds suitable for spin control.

Abstract

We report on the development and testing of a coplanar stripline antenna that is designed for integration in a magneto-photoluminescence experiment to allow coherent control of individual electron spins confined in single self-assembled semiconductor quantum dots. We discuss the design criteria for such a structure which is multi-functional in the sense that it serves not only as microwave delivery but also as electrical top gate and shadow mask for the single quantum dot spectroscopy. We present test measurements on hydrogenated amorphous silicon, demonstrating electrically detected magnetic resonance using the in-plane component of the oscillating magnetic field created by the coplanar stripline antenna necessary due to the particular geometry of the quantum dot spectroscopy. From reference measurements using a commercial electron spin resonance setup in combination with finite element calculations simulating the field distribution in the structure, we obtain an average magnetic field of ~0.2mT at the position where the quantum dots would be integrated into the device. The corresponding pi-pulse time of ~0.3us fully meets the requirements set by the high sensitivity optical spin read-out scheme developed for the quantum dot.