超冷离子源研究进展

Research progress of ultracold ion source

纳米离子束是制备束斑直径在微纳米尺度荷能离子束的先进技术,主要应用于高分辨和高精度的离子束分析、离子束加工和离子束材料改性研究,在材料分析、微纳加工、微电子器件制造和量子计算等方面发挥着重要的作用.高品质离子源作为纳米离子束装置的关键部件,其性能指标直接决定着该装置的技术水平.然而,目前常用的传统离子源存在离子种类单一、能散高和结构复杂等问题,已经难以满足新应用场景下的多离子种类和高分辨的要求,突显出研发新型离子源的重要性和迫切性.随着激光冷却技术的日臻成熟,基于光电离冷原子和激光冷却离子技术可以获得温度在mK甚至μK量级的超冷离子,其低温和易于操控等典型特征极大地促进了超冷离子源的发展.超冷离子具有极小的横向速度发散,可以显著提升离子源的亮度和发射度等品质参数,为纳米离子束技术的革新带来了巨大的发展机遇.因此,超冷离子源的研究对于实现更高亮度、更小尺寸、更低能散、更多样化离子种类以及结构更简化的高品质离子源具有重要的意义.本文综述了近年来超冷离子源的研究进展,从制备原理、产生方式以及典型应用等方面介绍了磁光阱离子源、冷原子束离子源和超冷单离子源在基础研究和应用技术研发方面取得的重要成果,并对超冷离子源的未来发展和应用前景进行了展望.

Nanobeam is an advanced technology for preparing charged ion beams with spot diameters on a nanometer scale,and mainly used for high-resolution and high-precision ion beam analysis,ion beam fabrication and ion beam material modification research.The nanobeam devices play an important role in realizing material analysis,micro/nano fabrication,microelectronic device manufacturing and quantum computing.The highquality ion source is one of the key components of nanobeam device,the performance of which directly affects the resolution and precision of the nanobeam system.However,the traditional ion source used in this system is limited to available ionic species,large energy spread and complex structure.These issues hinder their ability to meet emerging application scenarios that require multi-ion types and high resolution.This emphasizes the importance of creating newion sources as soon as possible.With the development of laser cooling technology,ultracold ions with temperatures in the range of mK or evenμK can be obtained based on photoionization of cold atoms and laser cooling of ions.The typical characteristics of low temperature and easy operation greatly promote the emergence of ultracold ion sources.The ultracold ions exhibit extremely small transverse velocity divergence,which can significantly enhance the brightness and emittance quality parameters of the ion source,bringing great opportunities for innovating nanoion beam technology.Therefore,the research on ultracold ion sources is of great significance for achieving highquality ion sources with higher brightness,smaller size,lower energy dispersion,more diverse ion species,and simplified structure.Here,we introduce the important achievements in basic research and application technology development of magneto-optical trap ion sources,cold atomic beam ion sources,and ultracold single ion sources from the aspects of preparation principles,generation methods,and typical applications,and review the recent research progress of ultracold ion sources.Finally,we provide an outlook on the future development and application prospects of ultracold ion sources.