尋找一個容易被制造、處理和操控的量子架構，一直是學術界、工業界和國防領域的焦點。實現這樣的架構將使我們能夠工程化量子技術。金剛石和碳化硅（SiC）已經被證明是工程量子通信、量子網絡和量子存儲設備的合適平臺。在硅、SiC、金剛石和其他半導體化合物中，電離供體和受體之間的轉變已經被理論模擬并在實驗中觀察到。盡管供體–受體對（DAP）系統已經被廣泛研究了幾十年，但它們在量子信息科學中的應用卻是在近年來才開始被考慮的。

來自美國芝加哥大學普利茲克分子工程學院的Giulia Galli?教授團隊，提出了一種利用寬禁帶半導體中DAP之間靜態偶極–偶極耦合的量子科學平臺，以實現固態中的光可控、長距相互作用。

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

他們特別關注了SiC和金剛石。首先，為了評估DAPs是否能在固態中促進長程量子相互作用，作者研究了DAPs的電子結構，特別是它們在宿主材料帶隙中相應的電子態。他們分析了幾個供體和受體上的電荷躍遷能級，并計算了它們的結合能。其次，通過確定特定DAPs的零聲子線和光致發光光譜，他們評估了是否可以在實驗上分辨出距離越來越遠DAPs的零聲子線。

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

作者計算了使DAP具有光可控長程相互作用的電偶極矩的大小，以表明在10 nm長度尺度以上強相互作用確實可以實現。最后，他們提供了一些DAPs輻射壽命的數量級估計。

Fig. 4 Stark shift of donor-acceptor pairs.

該工作表明，DAPs是一個很有前途的平臺，能工程化固體點缺陷之間可光學處理的遠程相互作用，以實現量子技術。該文最近發布于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及其翻譯

Donor-acceptor pairs in wide-bandgap semiconductors for quantum technology applications (量子技術應用中寬帶隙半導體中的供體–受體對)

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，我們提出了一個量子科學平臺，該平臺利用寬禁帶半導體中供體–受體對（DAPs）之間的偶極–偶極耦合，以實現對固態缺陷的光學可控長程相互作用。我們采用密度泛函理論（DFT）計算，深入研究了金剛石和碳化硅（SiC）中由不同替代點缺陷形成DAPs的電子結構和相互作用。利用約束DFT，我們確定了最穩定的電荷態，計算了零聲子線，并將計算結果與簡單的供體–受體對（DAP）模型進行了比較。我們發現，金剛石和SiC中幾個DAPs的基態和激發態之間的極化差異導致了異常大的電偶極矩。我們還預測了特定替代原子的光致發光光譜，發現雖然金剛石中的B-N對由于其大的電聲耦合而難以控制，但SiC中的DAPs，尤其是Al-N對，顯示出良好的光學可控性，成為實現長程光學可控相互作用的理想候選。