尋找一個(gè)容易被制造、處理和操控的量子架構(gòu)，一直是學(xué)術(shù)界、工業(yè)界和國防領(lǐng)域的焦點(diǎn)。實(shí)現(xiàn)這樣的架構(gòu)將使我們能夠工程化量子技術(shù)。金剛石和碳化硅（SiC）已經(jīng)被證明是工程量子通信、量子網(wǎng)絡(luò)和量子存儲(chǔ)設(shè)備的合適平臺(tái)。在硅、SiC、金剛石和其他半導(dǎo)體化合物中，電離供體和受體之間的轉(zhuǎn)變已經(jīng)被理論模擬并在實(shí)驗(yàn)中觀察到。盡管供體–受體對(duì)（DAP）系統(tǒng)已經(jīng)被廣泛研究了幾十年，但它們?cè)诹孔有畔⒖茖W(xué)中的應(yīng)用卻是在近年來才開始被考慮的。

來自美國芝加哥大學(xué)普利茲克分子工程學(xué)院的Giulia Galli?教授團(tuán)隊(duì)，提出了一種利用寬禁帶半導(dǎo)體中DAP之間靜態(tài)偶極–偶極耦合的量子科學(xué)平臺(tái)，以實(shí)現(xiàn)固態(tài)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(guān)注了SiC和金剛石。首先，為了評(píng)估DAPs是否能在固態(tài)中促進(jìn)長程量子相互作用，作者研究了DAPs的電子結(jié)構(gòu)，特別是它們?cè)谒拗鞑牧蠋吨邢鄳?yīng)的電子態(tài)。他們分析了幾個(gè)供體和受體上的電荷躍遷能級(jí)，并計(jì)算了它們的結(jié)合能。其次，通過確定特定DAPs的零聲子線和光致發(fā)光光譜，他們?cè)u(píng)估了是否可以在實(shí)驗(yàn)上分辨出距離越來越遠(yuǎn)DAPs的零聲子線。

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

作者計(jì)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(qiáng)相互作用確實(shí)可以實(shí)現(xiàn)。最后，他們提供了一些DAPs輻射壽命的數(shù)量級(jí)估計(jì)。

Fig. 4 Stark shift of donor-acceptor pairs.

該工作表明，DAPs是一個(gè)很有前途的平臺(tái)，能工程化固體點(diǎn)缺陷之間可光學(xué)處理的遠(yuǎn)程相互作用，以實(shí)現(xiàn)量子技術(shù)。該文最近發(fā)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(shù)應(yīng)用中寬帶隙半導(dǎo)體中的供體–受體對(duì))

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(gè)量子科學(xué)平臺(tái)，該平臺(tái)利用寬禁帶半導(dǎo)體中供體–受體對(duì)（DAPs）之間的偶極–偶極耦合，以實(shí)現(xiàn)對(duì)固態(tài)缺陷的光學(xué)可控長程相互作用。我們采用密度泛函理論（DFT）計(jì)算，深入研究了金剛石和碳化硅（SiC）中由不同替代點(diǎn)缺陷形成DAPs的電子結(jié)構(gòu)和相互作用。利用約束DFT，我們確定了最穩(wěn)定的電荷態(tài)，計(jì)算了零聲子線，并將計(jì)算結(jié)果與簡單的供體–受體對(duì)（DAP）模型進(jìn)行了比較。我們發(fā)現(xiàn)，金剛石和SiC中幾個(gè)DAPs的基態(tài)和激發(fā)態(tài)之間的極化差異導(dǎo)致了異常大的電偶極矩。我們還預(yù)測(cè)了特定替代原子的光致發(fā)光光譜，發(fā)現(xiàn)雖然金剛石中的B-N對(duì)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(duì)，顯示出良好的光學(xué)可控性，成為實(shí)現(xiàn)長程光學(xué)可控相互作用的理想候選。