[论文解读] Strain-Engineered Deterministic Quantum Dots for Telecom O-Band Emission Using Buried Stressors

Imad Limame, Ching‐Wen Shih+8 more|arXiv (Cornell University)|Mar 24, 2026

Semiconductor Quantum Structures and Devices被引用 0

一句话总结

论文展示了通过埋藏 AlAs/Al2O3 应力源实现现场可控的 InGaAs/GaAs 量子点在电信 O 波段（约1260–1295 nm）发射，并在无应力减小层的情况下实现确定性定位与红移发射，单光子发射在高达 40 K 时稳定，并有理论支撑的进一步红移设计。

ABSTRACT

The deterministic realization of quantum light sources operating at telecom wavelengths is essential for long-distance fiber-based quantum communication and distributed quantum computing. In this work, we demonstrate that telecom O-band emission can be achieved from site-controlled InGaAs/GaAs quantum dots (QDs). Our concept utilizes a buried AlAs/Al$_2$O$_3$ stressor layer with the unique feature that induces a well-defined and controllable tensile strain field at the growth surface, enabling both a redshift of QD emission to the $\sim$1.3~μm range and site-selective nucleation at the mesa centers. This concept eliminates not only the need for strain-reducing layers (SRLs), which are known to degrade optical coherence, but also provides spatial control and spectral tunability. The grown telecom QDs show pure single-photon emission with $g^{(2)}(τ) = (5.0 \pm 1.0) imes 10^{-2}$ at 4 K and $(2.8 \pm 0.3) imes 10^{-1}$ at 77~K, demonstrating the quantum nature and thermal stability of the emitters. The emission characteristics of complex excitonic states are analyzed using 8-band $k \cdot p$ and configuration-interaction modeling, which quantitatively reproduces the experimental observations. Finally, we present a theory-supported strategy to further redshift the emission toward the center of the O-band and beyond by employing a multi-buried-stressor approach. This combined framework of experiment and theory establishes the buried stressor concept as a scalable route toward highly coherent, position-controlled O-band quantum emitters compatible with industrial photonic integration.

研究动机与目标

• 实现来自现场控制的 InGaAs/GaAs 量子点在不使用应力减小层（SRLs）的情况下发射到电信 O 波段。
• 展示由埋藏拉伸应变驱动的台座中心处的现场选择性成核。
• 展示纯单光子发射并在不同温度下量化光谱/时间特性。
• Develop a theory-supported framework combining k·p and configuration-interaction modeling to interpret and guide performance.

提出的方法

• 通过埋藏 AlAs/Al2O3 应力层进行现场控制量子点的外延生长，并通过横向氧化形成氧化孔径。
• 方形台座的模式化、选择性氧化以及无 SRLs 或 MB 层的覆盖生长。
• 利用透射电子发光和显微光致发光光谱来识别 O 波段量子点发射及激子复合态。
• 8 价带 k·p 加上配置相互作用（CI）计算以建模单粒子态和多粒子激子谱。
• CI 基底包含 12 个电子态和 24 个空穴态（SDCI 近似）以计算结合能和细结构分裂（FSS）。
• 有限元/弹性建模以关联应力源几何与表面拉应变及发射红移。

Figure 1: Optical characterization of O-band SCQDs using CL. (a) CL spectrum of the mesa’s central region (black trace) and from an off-center region (red trace). The inset shows a magnified view of the QD emission in the telecom O-band. The spectral segment highlighted in yellow, spanning from 1260

实验结果

研究问题

• RQ1 埋藏应力源是否能够诱导确定性、现场控制的 InGaAs/GaAs 量子点在无 SRLs 的情况下发射到电信 O 波段？
• RQ2 台座几何、埋藏应力源布置与发射波长、密度、相干性之间的关系如何？
• RQ3 八带 k·p 与 CI 理论在多大程度上能够重现观测到的激子能量、FSS 与结合能？
• RQ4 哪些策略（如多埋藏应力源设计）可以将 O 波段发射进一步向中心及更深处推进？

主要发现

• 在无 SRLs 的情况下实现了来自现场控制的量子点的电信 O 波段发射（约1260–1280 nm）。
• X 发射在 4 K 时的单光子纯度 g(2)(0) = (5.0 ± 1.0) × 10^-2，在 77 K 时为 (2.8 ± 0.3) × 10^-1。
• X 的 FSS 为 (60.0 ± 0.2) μeV，CI 建模在 ~70% In 含量、3 nm 高、34 nm 基底的量子点上重现了已测的结合能。
• 埋藏应力源可在单个约 ~0.40% 与三个应力源约 ~1.41% 的表面拉伸应变，实现波长调谐和更高的铟掺杂。
• 提出多埋藏应力源方法，通过设计应力轮廓和孔径几何，朝向 O 波段中心及更深处实现更大红移。
• 证明了空间定位精度，平均位移为十纳米到百纳米数量级，确认现场控制成核。

Figure 2: (a) Waterfall plot displaying the µPL emission from a selected SCQD under 1130 nm pulsed excitation, with pump powers ranging from 14 to 500 µW at 4 K. Insets show Gaussian fits of the exciton ( $X$ ) and negatively charged exciton ( $X^{-}$ ) lines. (b) Polarization-resolved $\mu$ PL spec