Ma pulse a Attosecond amavumbula zinsinsi za kuchedwa kwa nthawi

Kugunda kwa Attosecondkuwulula zinsinsi za kuchedwa kwa nthawi
Asayansi ku United States, mothandizidwa ndi ma attosecond pulses, avumbulutsa zambiri zatsopano zokhudzamphamvu ya photoelectric: ndikutulutsa kwa mphamvu ya photoelectricKuchedwa kumafika pa ma attosecond 700, nthawi yayitali kwambiri kuposa momwe ankayembekezera kale. Kafukufuku waposachedwapayu akutsutsa zitsanzo zomwe zilipo kale ndipo amathandizira kumvetsetsa bwino momwe ma elekitironi amagwirira ntchito, zomwe zimapangitsa kuti pakhale ukadaulo monga ma semiconductors ndi ma solar cell.
Mphamvu ya photoelectric imatanthauza chodabwitsa chakuti kuwala kukawala pa molekyulu kapena atomu pamwamba pa chitsulo, photon imalumikizana ndi molekyulu kapena atomu ndikutulutsa ma elekitironi. Mphamvu imeneyi si imodzi mwa maziko ofunikira a quantum mechanics, komanso imakhudza kwambiri sayansi yamakono ya fizikisi, chemistry ndi zipangizo. Komabe, m'munda uwu, nthawi yotchedwa photoemission delay time yakhala nkhani yotsutsana, ndipo mitundu yosiyanasiyana ya chiphunzitso yafotokoza izi m'magawo osiyanasiyana, koma palibe mgwirizano umodzi womwe wapangidwa.
Pamene gawo la sayansi ya attosecond lapita patsogolo kwambiri m'zaka zaposachedwa, chida chatsopanochi chimapereka njira yosayerekezeka yofufuzira dziko la microscopic. Mwa kuyeza molondola zochitika zomwe zimachitika nthawi yochepa kwambiri, ofufuza amatha kupeza zambiri zokhudza momwe tinthu tating'onoting'ono timagwirira ntchito. Mu kafukufuku waposachedwa, adagwiritsa ntchito ma X-ray amphamvu kwambiri opangidwa ndi gwero lowunikira la coherent ku Stanford Linac Center (SLAC), lomwe lidatenga gawo limodzi mwa magawo biliyoni a sekondi (attosecond), kuti apangitse ma electron apakati kukhala "oyera" ndikutulutsa molekyulu yosangalatsa.
Pofuna kusanthula mozama njira za ma elekitironi otulutsidwa awa, adagwiritsa ntchito ma excited payokhama pulse a laserkuyeza nthawi yotulutsa ma elekitironi mbali zosiyanasiyana. Njira imeneyi inawathandiza kuwerengera molondola kusiyana kwakukulu pakati pa nthawi zosiyanasiyana zomwe zimachitika chifukwa cha kuyanjana pakati pa ma elekitironi, kutsimikizira kuti kuchedwako kumatha kufika pa ma attosecond 700. Ndikofunikira kudziwa kuti kupezeka kumeneku sikungotsimikizira malingaliro ena am'mbuyomu, komanso kumabweretsa mafunso atsopano, zomwe zimapangitsa kuti mfundo zoyenera ziwunikidwenso ndikusinthidwa.
Kuphatikiza apo, kafukufukuyu akuwonetsa kufunika koyesa ndi kutanthauzira kuchedwa kwa nthawi kumeneku, komwe ndikofunikira kwambiri kuti timvetsetse zotsatira za mayeso. Mu crystallography ya mapuloteni, kujambula zamankhwala, ndi ntchito zina zofunika zokhudzana ndi kuyanjana kwa ma X-ray ndi zinthu, deta iyi idzakhala maziko ofunikira pakukonza njira zaukadaulo ndikukweza mtundu wa kujambula. Chifukwa chake, gululi likukonzekera kupitiliza kufufuza mphamvu zamagetsi zamitundu yosiyanasiyana ya mamolekyulu kuti liwulule zambiri zatsopano zokhudza machitidwe amagetsi m'machitidwe ovuta kwambiri komanso ubale wawo ndi kapangidwe ka mamolekyulu, ndikuyika maziko olimba a data pakupanga ukadaulo wogwirizana mtsogolo.