Attosecond pulsestyhila iimfihlo zokulibaziseka kwexesha
Izazinzulu zaseUnited States, ngoncedo lwe-attosecond pulses, ziye zatyhila ulwazi olutsha malunga nentsholongwane.isiphumo sombane: iukukhutshwa kweefoto zombaneulibaziseko lufikelela kwi-700 attoseconds, ixesha elide kunoko bekulindelekile ngaphambili. Olu phando lwamva nje lucela umngeni kwiimodeli ezikhoyo zethiyori kwaye lunegalelo ekuqondeni okunzulu konxibelelwano phakathi kwee-electron, okukhokelela kuphuhliso lobuchwepheshe obufana ne-semiconductors kunye neeseli zelanga.
Impembelelo ye-photoelectric ibhekisela kwinto yokuba xa ukukhanya kukhanya kwi-molecule okanye i-athomu kwindawo yesinyithi, i-photon isebenzisana ne-molecule okanye i-athomu kwaye ikhupha ii-electron. Esi siphumo asikho nje esinye seziseko ezibalulekileyo ze-quantum mechanics, kodwa zinempembelelo enkulu kwi-physics yanamhlanje, i-chemistry kunye nesayensi yezinto. Nangona kunjalo, kule ntsimi, ixesha elibizwa ngokuba lixesha lokulibaziseka kwe-photoemission liyisihloko esiphikisanayo, kwaye iimodeli ezahlukeneyo zeethiyori zichaze kwiidigri ezahlukeneyo, kodwa akukho mvumelwano edibeneyo eyenziweyo.
Njengoko icandelo lesayensi ye-attosecond liye laphucuka ngokumangalisayo kwiminyaka yakutshanje, esi sixhobo sivelayo sibonelela ngendlela engazange ibonwe ngaphambili yokuphonononga umhlaba we-microscopic. Ngokulinganisa ngokuchanekileyo iziganeko ezenzeka kwizikali zexesha elifutshane kakhulu, abaphandi bayakwazi ukufumana ulwazi oluninzi malunga nokuziphatha okuguquguqukayo kwamasuntswana. Kuphononongo lwamva nje, basebenzise uthotho lwe-X-ray ye-high-intensity pulses eveliswa ngumthombo wokukhanya ohambelanayo kwiziko laseStanford Linac (i-SLAC), eyahlala kuphela ibhiliyoni yesibini (i-attosecond), i-ionize i-electrons eziphambili kunye "nokukhaba" ngaphandle kwe-molecule enomdla.
Ukuhlalutya ngakumbi iitrajectories zezi electron zikhutshiweyo, basebenzise ngabanye bevuyaimithambo laserukulinganisa amaxesha okukhutshwa kwee-electron kumacala ahlukeneyo. Le ndlela yabavumela ukuba babale ngokuchanekileyo ukungafani okuphawulekayo phakathi kwamaxesha ahlukeneyo okubangelwa ukusebenzisana phakathi kwe-electron, eqinisekisa ukuba ukulibaziseka kunokufikelela kwi-700 attoseconds. Kuyafaneleka ukuba uqaphele ukuba oku kufunyaniswayo akuqinisekisi kuphela ezinye iingcamango zangaphambili, kodwa kwakhona kuphakamisa imibuzo emitsha, ukwenza iingcamango ezifanelekileyo kufuneka zihlolwe kwakhona kwaye zihlaziywe.
Ukongezelela, uphando lugxininisa ukubaluleka kokulinganisa kunye nokutolika oku kulibaziseka kwexesha, okubalulekileyo ekuqondeni iziphumo zovavanyo. Kwiprotein crystallography, i-imaging yonyango, kunye nezinye izicelo ezibalulekileyo ezibandakanya ukusebenzisana kwe-X-rays kunye nomcimbi, ezi nkcukacha ziya kuba sisiseko esibalulekileyo sokuphucula iindlela zobugcisa kunye nokuphucula umgangatho wokucinga. Ngoko ke, iqela liceba ukuqhubeka nokuphonononga i-electronic dynamics yeentlobo ezahlukeneyo zeamolekyu ukwenzela ukutyhila ulwazi olutsha malunga nokuziphatha kombane kwiinkqubo eziyinkimbinkimbi kunye nobudlelwane babo kunye nesakhiwo seemolekyuli, ukubeka isiseko sedatha esomeleleyo sokuphuhliswa kobuchwepheshe obuhambelanayo kwixesha elizayo.
Ixesha lokuposa: Sep-24-2024