![\"Experiment](\"https:\/\/www.osel.cz\/popisek.php?popisek=44589&img=44_12.jpeg\" "\\"Experiment")
<\/a><\/p>\nExperiment s\u00a0jadern\u00fdmi hodinami. Kredit: Chuankun Zhang\/JILA.<\/p>\n
V\u00a0sou\u010dasn\u00e9 dob\u011b jsou nejp\u0159esn\u011bj\u0161\u00edmi hodinami atomov\u00e9 hodiny. \u010cas m\u011b\u0159\u00ed pomoc\u00ed frekvenc\u00ed z\u00e1\u0159en\u00ed vznikaj\u00edc\u00edch p\u0159i p\u0159eskoc\u00edch elektron\u016f mezi energetick\u00fdmi hladinami atomu. Tyto frekvence jsou mimo\u0159\u00e1dn\u011b stabiln\u00ed, a tud\u00ed\u017e i velmi dob\u0159e p\u0159edv\u00eddateln\u00e9. K ur\u010den\u00ed uplynul\u00e9ho \u010dasu sta\u010d\u00ed po\u010d\u00edtat jejich kmity.<\/p>\n
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Experiment \u010d\u00ednsk\u00e9ho t\u00fdmu. Kredit: Huang et al. (2026), arXiv.<\/p>\n Podobn\u011b by mohly fungovat i jadern\u00e9 hodiny. Nam\u00edsto energetick\u00fdch hladin elektron\u016f by vyu\u017e\u00edvaly p\u0159echody mezi energetick\u00fdmi stavy proton\u016f a neutron\u016f uvnit\u0159 atomov\u00e9ho j\u00e1dra. Atomov\u00e9 j\u00e1dro je mnohem l\u00e9pe izolov\u00e1no od okoln\u00edho prost\u0159ed\u00ed a je t\u00edm p\u00e1dem m\u00e9n\u011b citliv\u00e9 na ru\u0161iv\u00e9 vlivy vn\u011bj\u0161\u00edch elektrick\u00fdch a magnetick\u00fdch pol\u00ed. Jadern\u00e9 hodiny by m\u011bly b\u00fdt je\u0161t\u011b p\u0159esn\u011bj\u0161\u00ed a odoln\u011bj\u0161\u00ed ne\u017e sou\u010dasn\u00e9 atomov\u00e9 hodiny.<\/p>\n \u00a0<\/p>\n Jak to ve v\u011bd\u011b b\u00fdv\u00e1 a\u017e pozoruhodn\u011b \u010dasto, nakonec sou\u010dasn\u011b usp\u011bly dva nez\u00e1visl\u00e9 v\u00fdzkumn\u00e9 t\u00fdmy a sestrojily vytou\u017een\u00e9 funk\u010dn\u00ed jadern\u00e9 hodiny. Vedli je Beichen Huang z \u010d\u00ednsk\u00e9 Tsinghua University Luca Toscani De Col z\u00a0rakousk\u00e9ho Vienna Center for Quantum Science and Technology. Jejich za\u0159\u00edzen\u00ed v\u00a0obou p\u0159\u00edpadech vyu\u017e\u00edvaj\u00ed k m\u011b\u0159en\u00ed \u010dasu s mimo\u0159\u00e1dnou p\u0159esnost\u00ed atomov\u00e9 j\u00e1dro thoria-229. Tato technologie by mohla p\u0159ekonat i nejlep\u0161\u00ed atomov\u00e9 hodiny, kter\u00e9 jsou dnes k dispozici.<\/p>\n \u00a0<\/p>\n Experiment rakousk\u00e9ho t\u00fdmu. Kredit: Toscani De Col et al. (2026), arXiv.<\/p>\n Ze v\u0161ech zn\u00e1m\u00fdch atomov\u00fdch jader je pro tento \u00fa\u010del se sou\u010dasn\u00fdmi technologiemi vhodn\u00e9 pouze thorium-229. Jde o to, \u017ee energetick\u00fd p\u0159echod v jeho j\u00e1d\u0159e m\u00e1 v\u00fdjime\u010dn\u011b n\u00edzkou energii a lze jej lze vyvolat a m\u011b\u0159it pomoc\u00ed laserov\u00e9ho sv\u011btla. Sestaven\u00ed funk\u010dn\u00edch jadern\u00fdch hodin se ale p\u0159esto uk\u00e1zalo jako mimo\u0159\u00e1dn\u011b n\u00e1ro\u010dn\u00fd \u00fakol. Jde o to, \u017ee pot\u0159ebn\u00e9 laserov\u00e9 z\u00e1\u0159en\u00ed se nach\u00e1z\u00ed ve vakuov\u00e9 ultrafialov\u00e9 oblasti spektra (VUV, pod 200 nm), se kterou je technicky velmi obt\u00ed\u017en\u00e9 pracovat.<\/p>\n Oba t\u00fdmy to vy\u0159e\u0161ily podobn\u011b. J\u00e1dra thoria-229 vlo\u017eily do krystal\u016f fluoridu v\u00e1penat\u00e9ho a zkoumaly je pomoc\u00ed kontinu\u00e1ln\u00edho laseru na vlnov\u00e9 d\u00e9lce cca 148 nanometr\u016f. \u010c\u00ednsk\u00fd t\u00fdm pou\u017eil v\u00fdkonn\u011bj\u0161\u00ed laser, zat\u00edmco v Rakousku pracovali s krystalem obsahuj\u00edc\u00edm vy\u0161\u0161\u00ed koncentraci jader thoria. Jadern\u00e9 hodiny jsou mocn\u00fdm n\u00e1strojem, jak pro z\u00e1kladn\u00ed v\u00fdzkum, tak i pro aplikace, t\u0159eba v\u00a0naviga\u010dn\u00edch syst\u00e9mech.<\/p>\n \u00a0<\/p>\n Video: Quo Vadis Thorium-229? Recent progress towards a „Nuclear Clock“<\/p>\n \n \u00a0<\/p>\n Literatura<\/p>\n Phys.org 12. 6. 2026.<\/a><\/p>\n<\/a><\/p>\n<\/a><\/p>\n