宽禁带半导体中供体-受体对：理想的量子科学平台

寻找一个容易被制造、处理和操控的量子架构，一直是学术界、工业界和国防领域的焦点。实现这样的架构将使我们能够工程化量子技术。金刚石和碳化硅（SiC）已经被证明是工程量子通信、量子网络和量子存储设备的合适平台。在硅、SiC、金刚石和其他半导体化合物中，电离供体和受体之间的转变已经被理论模拟并在实验中观察到。尽管供体–受体对（DAP）系统已经被广泛研究了几十年，但它们在量子信息科学中的应用却是在近年来才开始被考虑的。

来自美国芝加哥大学普利兹克分子工程学院的Giulia Galli 教授团队，提出了一种利用宽禁带半导体中DAP之间静态偶极–偶极耦合的量子科学平台，以实现固态中的光可控、长距相互作用。

Fig. 2 Electric dipole moments of donor-acceptor pairs.

他们特别关注了SiC和金刚石。首先，为了评估DAPs是否能在固态中促进长程量子相互作用，作者研究了DAPs的电子结构，特别是它们在宿主材料带隙中相应的电子态。他们分析了几个供体和受体上的电荷跃迁能级，并计算了它们的结合能。其次，通过确定特定DAPs的零声子线和光致发光光谱，他们评估了是否可以在实验上分辨出距离越来越远DAPs的零声子线。

Fig. 3 Zero-phonon lines of donor-acceptor pairs.

作者计算了使DAP具有光可控长程相互作用的电偶极矩的大小，以表明在10 nm长度尺度以上强相互作用确实可以实现。最后，他们提供了一些DAPs辐射寿命的数量级估计。

Fig. 4 Stark shift of donor-acceptor pairs.

该工作表明，DAPs是一个很有前途的平台，能工程化固体点缺陷之间可光学处理的远程相互作用，以实现量子技术。该文最近发布于npj Computational Materials  10: 7 (2024)。

Editorial Summary

The search for a quantum architecture that can be easily fabricated, addressed, and manipulated has been at the forefront of academic, industrial, and defense efforts. Realizing such an architecture will enable us to engineer quantum technologies. Diamond and silicon carbide (SiC) have been demonstrated to be suitable platforms for engineering devices for quantum teleportation, quantum networks, and quantum memories. The transition between ionized donors and acceptors has been theoretically modelled and experimentally observed in many materials, including silicon, silicon carbide, diamond, and other compound semiconductors. Even though donor-acceptor pair (DAP) systems have been extensively studied for decades, only recently they have been considered for applications in quantum information science. 

A team led by Prof. Giulia Galli from the Pritzker School of Molecular Engineering, University of Chicago, proposed a quantum science platform utilizing the static electric dipole-dipole coupling between DAPs in wide bandgap semiconductors to realize optically controllable, long-range interactions in the solid-state. They focused their efforts specifically on SiC and diamond. First, to evaluate whether DAPs could facilitate long-range quantum interactions in the solid state, they investigated the electronic structure of DAPs, specifically the corresponding electronic states in the bandgap of their host materials. They computed the charge transition levels for several donors and acceptors and calculated their binding energies. Then, they determined the zero-phonon lines (ZPL) of specific DAPs and predicted their photoluminescence spectra to assess whether individual ZPL from increasingly distant pairs can be experimentally resolved. They computed the magnitude of electric dipole moments that enable DAPs to have optically controllable long-range interactions, and showed that strong interactions at longer than 10 nm length scales can indeed be realized. Finally, they provided estimates of the order of magnitude of the radiative lifetimes of some of the DAPs. Their findings suggest that DAPs are a promising platform to engineer optically addressable long range interactions between point-defects in solids for the realization of quantum technologies. This article was recently published in npj Computational Materials  10: 7 (2024).

原文Abstract及其翻译

Donor-acceptor pairs in wide-bandgap semiconductors for quantum technology applications (量子技术应用中宽带隙半导体中的供体–受体对)

Anil Bilgin, Ian N. Hammock, Jeremy Estes, Yu Jin, Hannes Bernien, Alexander A. High & Giulia Galli 

Abstract We propose a quantum science platform utilizing the dipole-dipole coupling between donor-acceptor pairs (DAPs) in wide bandgap semiconductors to realize optically controllable, long-range interactions between defects in the solid state. We carry out calculations based on density functional theory (DFT) to investigate the electronic structure and interactions of DAPs formed by various substitutional point-defects in diamond and silicon carbide (SiC). We determine the most stable charge states and evaluate zero phonon lines using constrained DFT and compare our results with those of simple donor-acceptor pair (DAP) models. We show that polarization differences between ground and excited states lead to unusually large electric dipole moments for several DAPs in diamond and SiC. We predict photoluminescence spectra for selected substitutional atoms and show that while B-N pairs in diamond are challenging to control due to their large electron-phonon coupling, DAPs in SiC, especially Al-N pairs, are suitable candidates to realize long-range optically controllable interactions.

摘要 在本工作中，我们提出了一个量子科学平台，该平台利用宽禁带半导体中供体–受体对（DAPs）之间的偶极–偶极耦合，以实现对固态缺陷的光学可控长程相互作用。我们采用密度泛函理论（DFT）计算，深入研究了金刚石和碳化硅（SiC）中由不同替代点缺陷形成DAPs的电子结构和相互作用。利用约束DFT，我们确定了最稳定的电荷态，计算了零声子线，并将计算结果与简单的供体–受体对（DAP）模型进行了比较。我们发现，金刚石和SiC中几个DAPs的基态和激发态之间的极化差异导致了异常大的电偶极矩。我们还预测了特定替代原子的光致发光光谱，发现虽然金刚石中的B-N对由于其大的电声耦合而难以控制，但SiC中的DAPs，尤其是Al-N对，显示出良好的光学可控性，成为实现长程光学可控相互作用的理想候选。