Disorder-independent hole spin manipulation by hopping

TL;DR

This paper investigates disorder-dependent hole spin manipulation via hopping in quantum dots, demonstrating limitations with reduced disorder and proposing a disorder-independent alternative using squeezed quantum dots for scalable quantum computing.

Contribution

It reveals the disorder dependence of hopping-based spin manipulation and introduces a novel approach with squeezed quantum dots to achieve disorder-independent control.

Findings

Hopping-based spin manipulation effectiveness decreases with reduced disorder.

Proposed squeezed quantum dots enable disorder-independent spin control.

Method enhances scalability prospects for hole-spin quantum computing.

Abstract

Spin manipulation by hopping has recently emerged as a promising strategy to control hole spins in quantum dots using exclusively baseband control, thereby mitigating power dissipation and high-frequency management constraints in large-scale architectures. Unlike conventional approaches such as electron dipole spin resonance (EDSR), this mechanism exploits dot-to-dot variations of the spin precession axes to enable spin rotations. However, it is intrinsically disorder-dependent: in the absence of sufficient variability, the precession axes remain aligned and spin manipulation becomes ineffective. This fundamental reliance on disorder raises concerns regarding its compatibility with the long-term evolution of spin-qubit platforms toward improved material quality, cleaner interfaces, and enhanced device reproducibility. Here, we numerically assess the viability of spin manipulation by hopping as a function of disorder strength and demonstrate that its implementation is indeed increasingly constrained as disorder is reduced. To overcome this limitation, we propose an alternative strategy based on hopping between intentionally squeezed quantum dots. This approach retains the advantages of baseband control while being independent of disorder and robust against moderate variability, thereby offering improved prospects for scalable hole-spin quantum computing architectures.