Iipulses ze-Attosecondukutyhila iimfihlo zokulibaziseka kwexesha
Izazinzulu eMelika, ngoncedo lwee-attosecond pulses, zityhile ulwazi olutsha malungaimpembelelo yefotoelectric: iukukhutshwa kwe-photoelectricUkulibaziseka kufikelela kwi-attoseconds ezingama-700, ixesha elide kakhulu kunokuba bekulindelwe ngaphambili. Olu phando lwamva nje lucel’ umngeni kwiimodeli zethiyori ezikhoyo kwaye lunegalelo ekuqondeni nzulu ukusebenzisana phakathi kwee-elektroni, nto leyo ekhokelela kuphuhliso lwetekhnoloji efana nee-semiconductors kunye neeseli zelanga.
Isiphumo se-photoelectric sibhekisa kwinto yokuba xa ukukhanya kukhanya kwi-molecule okanye i-atom kumphezulu wesinyithi, i-photon idibana ne-molecule okanye i-atom ize ikhuphe ii-electron. Esi siphumo asisosinye nje seziseko ezibalulekileyo ze-quantum mechanics, kodwa sikwanefuthe elikhulu kwi-physics yanamhlanje, i-chemistry kunye nesayensi yezinto. Nangona kunjalo, kweli candelo, ixesha lokulibaziseka kwe-photoemission libe yingxoxo ephikisanayo, kwaye iimodeli ezahlukeneyo zethiyori ziye zachaza oko ngokwamanqanaba ahlukeneyo, kodwa akukho mvumelwano idibeneyo eyenziweyo.
Njengoko intsimi yesayensi ye-attosecond iphucuke kakhulu kwiminyaka yakutshanje, esi sixhobo sivelayo sinika indlela engazange ibonwe ngaphambili yokuhlola ihlabathi le-microscopic. Ngokulinganisa ngokuchanekileyo iziganeko ezenzeka ngexesha elifutshane kakhulu, abaphandi bayakwazi ukufumana ulwazi oluthe kratya malunga nokuziphatha okuguquguqukayo kwamasuntswana. Kuphononongo lwamva nje, basebenzise uthotho lwee-pulses ze-X-ray ezinamandla kakhulu eziveliswe ngumthombo wokukhanya ohambelanayo kwiZiko leStanford Linac (SLAC), elithathe isiqingatha sebhiliyoni sesekhondi (attosecond), ukwenza i-ion ii-electron eziphambili kunye "nokukhaba" imolekyuli evusiweyo.
Ukuze bahlalutye ngakumbi iindlela ezisetyenziswa kwezi electron zikhutshiweyo, basebenzise ii-excited nganye nganyeiipulses zelaserukulinganisa amaxesha okukhutshwa kwee-elektroni kumacala ahlukeneyo. Le ndlela yabavumela ukuba babale ngokuchanekileyo umahluko obalulekileyo phakathi kwamaxesha ahlukeneyo abangelwa kukunxibelelana phakathi kwee-elektroni, iqinisekisa ukuba ukulibaziseka kunokufikelela kwi-attoseconds ezingama-700. Kubalulekile ukuqaphela ukuba oku kufunyaniswayo akuqinisekisi nje kuphela ezinye iingcamango zangaphambili, kodwa kukwaphakamisa nemibuzo emitsha, okwenza ukuba iingcamango ezifanelekileyo ziphinde zihlolwe kwaye zihlaziywe.
Ukongeza, olu phononongo lugxininisa ukubaluleka kokulinganisa nokutolika oku kulibaziseka kwexesha, okubaluleke kakhulu ekuqondeni iziphumo zovavanyo. Kwi-protein crystallography, i-medical imaging, kunye nezinye izicelo ezibalulekileyo ezibandakanya ukusebenzisana kwe-X-rays nezinto, ezi datha ziya kuba sisiseko esibalulekileyo sokwenza ngcono iindlela zobugcisa kunye nokuphucula umgangatho womfanekiso. Ke ngoko, iqela liceba ukuqhubeka nokuhlola amandla e-elektroniki eentlobo ezahlukeneyo zeemolekyuli ukuze kutyhilwe ulwazi olutsha malunga nokuziphatha kwe-elektroniki kwiinkqubo ezintsonkothileyo kunye nolwalamano lwazo nesakhiwo se-molekyuli, kubeka isiseko sedatha esiqinileyo sophuhliso lwetekhnoloji enxulumeneyo kwixesha elizayo.
Ixesha leposi: Sep-24-2024