[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"doc-detail-121042-en":3,"doc-seo-121042-105":30,"detail-sidebar-cat-0-en-105":91},{"code":4,"msg":5,"data":6},0,"success",{"doc_id":7,"user_id":8,"nickname":9,"user_avatar":10,"doc_module":4,"category_id":11,"category_name":12,"doc_title":13,"doc_description":14,"doc_content":15,"file_id":16,"file_url":17,"file_type":18,"file_size":19,"view_count":4,"is_deleted":4,"is_public":20,"is_downloadable":20,"audit_status":20,"page_count":21,"language":22,"language_code":23,"site_id":24,"html_lang":23,"table_of_contents":25,"faqs":26,"seo_title":27,"seo_description":14,"update_tm":28,"read_time":29},121042,2336464648322,"Aria","https://ap-avatar.wpscdn.com/avatar/2200025388227c56fec?_k=1778556882303663488",8,"Research & Report","Machine Learning Enhanced Quantum Optical Storage in Solids - Research Report","Quantum memory devices with high storage efficiency and bandwidth are critical for future quantum networks. This work applies passive optimization and machine-learning methods to improve atomic frequency comb (AFC) storage in a Tm3+ : YAG solid. A nearly six-fold enhancement in quantum memory efficiency is demonstrated while maintaining broadband performance, enabling coherent and single-photon-level storage with high signal-to-noise ratio. The optimization is designed to be broadly transferable to solid-state quantum memories.","Machine-Learning-Enhanced Quantum Optical Storage in Solids  \narXiv :2404 .04200v1 [ quant-ph] 5 Apr 2024  \nYisheng Lei, 1 Haechan An, 1, 2 Zongfeng Li, 1 and Mahdi Hosseini 1, 2, 􀀃  \n1 Department of Electrical and Computer Engineering and Applied Physics Program,  \nNorthwestern University, Evanston, IL 60208, USA  \n2 Elmore Family School of Electrical and Computer Engineering,  \nPurdue University, West Lafayette, Indiana 47907, USA  \n(Dated: April 8, 2024)  \nQuantum memory devices with high storage efficiency and bandwidth are essential elements for future quantum networks. Solid-state quantum memories can provide broadband storage, but they primarily suffer from low storage efficiency. We use passive optimization and machine learning techniques to demonstrate nearly a 6-fold enhancement in quantum memory efficiency. In this regime, we demonstrate coherent and single-photon-level storage with a high signal-to-noise ratio. The optimization technique presented here can be applied to most solid-state quantum memories to significantly improve the storage efficiency without compromising the memory bandwidth.  \nRare-earth-ion doped solids have been attractive platforms for the development of quantum optical memories [1] . The atomic frequency comb technique [2] has become the primary storage protocol in solids due to its broadband and low-noise properties. Typically, a 2-pulse train pumping sequence is used to perform spectral tailoring and create an atomic frequency comb (AFC) [3, 4] . Improving optical depth using impedance-matched resonators can be used to improve storage e􀀞ciency at the expense of lowering the memory bandwidth [5, 6] . Optimizing the pumping and preparation sequence is also crucial for better spectral tailoring leading to higher storage e􀀞ciency. In the case of laser-cooled atoms, machinelearning optimization has been deployed to enhance atom trapping and cooling [7, 8] . Such optimization has not been explored in the context of solid-state quantum memories. In this article, we perform machine-learning optimization of AFC quantum storage in a Tm3+ : YAG crystal. Tm3+ ions in solids have optical transition wavelengths close to those of Rubidium atoms, making them good candidates for building hybrid quantum networks [9] . Many experiments are performed using Tm3+ : YAG Crystal [3, 10], as well as Tm3+ : YGG Crystal [11, 12], Tm3+ : LiNbO3 crystal [13, 14], and Tm3+ ions doped in Lithium Niobate on Insulator [15] . Tm3+ ions in YAG crystal have a long optical coherence time of 100􀀖s, aground state lifetime of over 1s at around 1K, and a high branching ratio of 25%[16], making it a good system for spectral tailoring for photon storage. Our experiment is carried out using a tabletop cryostat at 3.5K and a magnetic 􀀜eld produced by a compact permanent magnet. We 􀀜rst passively enhance the optical depth without compromising bandwidth by routing the laser beam multiple times through the crystal. We then runa genetic algorithm to design a more e􀀞cient spectral preparation sequence. We show that the combination of these techniques can lead to a signi􀀜cant improvement in storage e􀀞ciency. We also demonstrate coherent and  \n􀀃 Corresponding author; [mh@northwestern.edu](mh@northwestern.edu)  \nsingle-photon-level storage with a high signal-to-noise ratio.  \nThe experimental setup is shown in Fig. 1 (a) . The Tm3+ : YAG crystal with dimensions 4×5× 10 mm (crys-  \n􀀖  \ntal axis h001i, h110i, h110i) has a doping concentration of 0.1% . The laser beam (Toptica DL Pro) propagates parallel to the h110i axis with linear polarization (E kh10i axis) . The optical transition 3 H4 ↔ 3 H6 occurs at a wavelength of 􀀕 =793.373 nm. A permanent magnet produces a magnetic 􀀜eld of 600 G along the h001i axis, lifting the degeneracy of Tm3+ ions with a nuclear spin of 1/2 . One of the two ground states can serve asa shelving state for spectral preparation. With spectral hole burning, its hole and side-holes (due to inhomogeneous broadening) are separated ","cbCaivo7MguIPKNv","https://ap.wps.com/l/cbCaivo7MguIPKNv","pdf",871997,1,5,"English","en",105,"# Motivation and approach\n# Atomic frequency comb protocol in solids\n# Material platform: Tm3+ : YAG properties\n# Experimental setup and characterization\n# Passive enhancement and genetic-algorithm spectral preparation\n# Storage results and performance metrics","[{\"question\":\"Why are high-efficiency, broadband quantum memory devices needed?\",\"answer\":\"They are essential building blocks for future quantum networks, enabling reliable storage of quantum optical signals with sufficient bandwidth and efficiency.\"},{\"question\":\"What does the paper improve in the AFC protocol?\",\"answer\":\"It improves quantum memory efficiency by optimizing optical depth without reducing bandwidth and by using machine learning (a genetic algorithm) to design a more efficient spectral preparation sequence.\"},{\"question\":\"Which material system is used for the experiments and why?\",\"answer\":\"The experiments use a Tm3+ : YAG crystal because Tm3+ ions offer suitable optical transitions and favorable coherence and lifetime properties for spectral tailoring and photon storage.\"}]","Machine Learning Enhanced Quantum Optical Storage in Solids - Research Report | PDF",1785733453,13,{"code":4,"msg":31,"data":32},"ok",{"site_id":24,"language":23,"slug":33,"title":13,"keywords":34,"description":14,"schema_data":35,"social_meta":86,"head_meta":88,"extra_data":90,"updated_unix":28},"machine-learning-enhanced-quantum-optical-storage-in-solids-research-report","",{"@graph":36,"@context":85},[37,54,68],{"@type":38,"itemListElement":39},"BreadcrumbList",[40,44,48,51],{"item":41,"name":42,"@type":43,"position":20},"https://docshare.wps.com","Home","ListItem",{"item":45,"name":46,"@type":43,"position":47},"https://docshare.wps.com/document/","Document",2,{"item":49,"name":12,"@type":43,"position":50},"https://docshare.wps.com/document/research-report/",3,{"item":52,"name":13,"@type":43,"position":53},"https://docshare.wps.com/document/machine-learning-enhanced-quantum-optical-storage-in-solids-research-report/121042/",4,{"url":52,"name":13,"@type":55,"author":56,"headline":13,"publisher":58,"fileFormat":61,"inLanguage":23,"description":14,"dateModified":62,"datePublished":62,"encodingFormat":61,"isAccessibleForFree":63,"interactionStatistic":64},"DigitalDocument",{"name":9,"@type":57},"Person",{"url":41,"name":59,"@type":60},"DocShare","Organization","application/pdf","2026-08-03",true,{"@type":65,"interactionType":66,"userInteractionCount":4},"InteractionCounter",{"@type":67},"ViewAction",{"@type":69,"mainEntity":70},"FAQPage",[71,77,81],{"name":72,"@type":73,"acceptedAnswer":74},"Why are high-efficiency, broadband quantum memory devices needed?","Question",{"text":75,"@type":76},"They are essential building blocks for future quantum networks, enabling reliable storage of quantum optical signals with sufficient bandwidth and efficiency.","Answer",{"name":78,"@type":73,"acceptedAnswer":79},"What does the paper improve in the AFC protocol?",{"text":80,"@type":76},"It improves quantum memory efficiency by optimizing optical depth without reducing bandwidth and by using machine learning (a genetic algorithm) to design a more efficient spectral preparation sequence.",{"name":82,"@type":73,"acceptedAnswer":83},"Which material system is used for the experiments and why?",{"text":84,"@type":76},"The experiments use a Tm3+ : YAG crystal because Tm3+ ions offer suitable optical transitions and favorable coherence and lifetime properties for spectral tailoring and photon storage.","https://schema.org",{"og:url":52,"og:type":87,"og:title":13,"og:site_name":59,"og:description":14},"article",{"robots":89,"canonical":52},"index,follow",{"doc_id":7,"site_id":24},{"code":4,"msg":5,"data":92},[93,97,101,105,109,114,119,122,127,130,134],{"id":20,"doc_module":4,"doc_module_name":46,"category_name":94,"show_sort_weight":95,"slug":96},"Story & Novel",90,"story-novel",{"id":47,"doc_module":4,"doc_module_name":46,"category_name":98,"show_sort_weight":99,"slug":100},"Literature",80,"literature",{"id":53,"doc_module":4,"doc_module_name":46,"category_name":102,"show_sort_weight":103,"slug":104},"Exam",70,"exam",{"id":21,"doc_module":4,"doc_module_name":46,"category_name":106,"show_sort_weight":107,"slug":108},"Comic",60,"comic",{"id":110,"doc_module":4,"doc_module_name":46,"category_name":111,"show_sort_weight":112,"slug":113},6,"Technology",50,"technology",{"id":115,"doc_module":4,"doc_module_name":46,"category_name":116,"show_sort_weight":117,"slug":118},7,"Healthcare",40,"healthcare",{"id":11,"doc_module":4,"doc_module_name":46,"category_name":12,"show_sort_weight":120,"slug":121},30,"research-report",{"id":123,"doc_module":4,"doc_module_name":46,"category_name":124,"show_sort_weight":125,"slug":126},9,"Religion & Spirituality",20,"religion-spirituality",{"id":125,"doc_module":4,"doc_module_name":46,"category_name":128,"show_sort_weight":125,"slug":129},"World Cup","world-cup",{"id":131,"doc_module":4,"doc_module_name":46,"category_name":132,"show_sort_weight":131,"slug":133},10,"Lifestyle","lifestyle",{"id":135,"doc_module":4,"doc_module_name":46,"category_name":136,"show_sort_weight":21,"slug":137},19,"General","general"]