中国科学家研制出一款光学钟，其稳定性和不确定度均超过10^{-19}水平，与全球少数顶级实验室相当。该成果发表于《计量学》杂志，可能助力中国在重新定义秒方面发挥领先作用。
中国已跻身全球顶级计时行列，研制出一款新型光学钟。该钟的关键参数——稳定性和不确定度——均超过10^{-19}水平，这一成就仅由少数实验室实现，包括美国国家标准与技术研究院和德国国家标准实验室。团队在本月发表于《Metrologia》杂志的论文中报告了这一结果，其精度已超过重新定义秒所需的阈值。国家广播电视台CCTV称，这“允许中国在这一努力中发挥领先作用”。研究人员戴（Dai）于3月7日对CCTV表示：“它为使用光学钟检验基础物理、改进下一代卫星导航并构建统一超精密全球时间标准奠定了坚实基础。”光学钟是最精确的计时装置，利用激光在极低温下捕获锶和铷等原子，通过电子在能级间跃迁时发出的光频率来测量时间。该钟可能发展为更小、更稳定和便携的空间版本。关键词提及合肥、中国科学技术大学等，表明研究主要在中国进行。
In an era dominated by digital precision, mechanical chronometer watches continue to symbolize the pursuit of accuracy in luxury horology. These timepieces, certified by independent bodies like COSC, connect modern enthusiasts to centuries-old innovations in timekeeping. The article explores their historical significance and ongoing relevance.
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New calculations suggest that time crystals, once seen as a quantum oddity, might serve as building blocks for highly precise quantum clocks. Researchers analyzed systems of quantum particles and found that time crystals maintain accuracy better when measuring short time intervals compared to conventional phases. This development could offer alternatives to existing timekeeping technologies.
Researchers led by Jun Ye at JILA in Boulder, Colorado, suggest placing an ultrastable laser in one of the moon's permanently shadowed craters to enhance navigation for lunar landers and rovers. The frigid, vibration-free environment near the lunar poles could enable unprecedented precision in timing and positioning. This setup might support activities from lunar timekeeping to satellite coordination.
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Researchers at EPFL have developed a method to measure the duration of ultrafast quantum events without using an external clock. By analyzing electron spin changes during photoemission, they found that transition times vary significantly based on a material's atomic structure. Simpler structures lead to longer delays, ranging from 26 to over 200 attoseconds.