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arXiv · 2604.03041

Spatial mapping of quantum-dot dynamics across multiple timescales at low temperature using remote asynchronous optical sampling

Gen Asambo·Riku Shibata·Yushiro Takahashi·Kouichi Akahane·Shinichi Watanabe·Junko Ishi-Hayase
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Abstract

Quantum dots (QDs) offer significant potential for applications in quantum information and optoelectronic devices; however, conventional time-resolved spectroscopy cannot generally simultaneously extract both long-lived relaxation dynamics and short-lived quantum beats from ensemble measurements. This limitation arises from the inherent trade-off between temporal resolution and total acquisition time. Here, we demonstrate that asynchronous optical sampling based on a fiber-delivered frequency comb enables simultaneous observation of QD dynamics across multiple timescales. By integrating a galvanometric scanner, we achieve spatial mapping over a $1 \times 1$-\si{\milli\meter}$^2$ area at 441 discrete points in 30.1~min, a measurement that would otherwise require more than 12~days. At each location, both quantum beats and relaxation lifetimes are resolved, giving physical insights into QD ensembles that were previously inaccessible and paving the way for rapid feedback in device fabrication.

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Gen Asambo, Riku Shibata, Yushiro Takahashi, Kouichi Akahane, Shinichi Watanabe, Junko Ishi-Hayase. 2026-04-03. Spatial mapping of quantum-dot dynamics across multiple timescales at low temperature using remote asynchronous optical sampling. https://arxiv.org/abs/2604.03041

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