Attosecond pulsesqhia cov secrets ntawm ncua sij hawm
Cov kws tshawb fawb hauv Tebchaws Meskas, nrog kev pab los ntawm attosecond pulses, tau tshaj tawm cov ntaub ntawv tshiab txog covcov nyhuv photoelectric: covphotoelectric emissionncua yog mus txog 700 attoseconds, ntev npaum li yav tas los xav tau. Qhov kev tshawb fawb tshiab no nyuaj rau cov qauv theoretical uas twb muaj lawm thiab ua rau muaj kev nkag siab tob txog kev sib cuam tshuam ntawm cov hluav taws xob, ua rau kev txhim kho cov thev naus laus zis xws li semiconductors thiab hnub ci hlwb.
Cov nyhuv photoelectric hais txog qhov tshwm sim uas thaum lub teeb ci rau ntawm lub molecule lossis atom ntawm cov hlau, cov photon cuam tshuam nrog cov molecule lossis atom thiab tso tawm electrons. Cov nyhuv no tsis yog tsuas yog ib qho ntawm lub hauv paus tseem ceeb ntawm quantum mechanics, tab sis kuj muaj kev cuam tshuam loj heev rau niaj hnub physics, chemistry thiab cov ntaub ntawv science. Txawm li cas los xij, hauv daim teb no, lub sijhawm hu ua photoemission ncua sij hawm tau yog lub ntsiab lus tsis sib haum xeeb, thiab ntau yam theoretical qauv tau piav qhia rau ntau qib, tab sis tsis muaj kev pom zoo tau tsim.
Raws li kev tshawb fawb ntawm attosecond science tau txhim kho tau zoo nyob rau xyoo tas los no, cov cuab yeej tshiab no muaj txoj hauv kev tsis tau pom dua los tshawb txog lub ntiaj teb microscopic. Los ntawm kev ntsuas qhov xwm txheej uas tshwm sim ntawm lub sijhawm luv luv, cov kws tshawb fawb muaj peev xwm tau txais cov ntaub ntawv ntau ntxiv txog tus cwj pwm zoo ntawm cov khoom. Nyob rau hauv txoj kev tshawb no tshiab, lawv siv ib tug series ntawm high-kev siv X-ray pulses uas ua los ntawm lub coherent lub teeb qhov chaw ntawm lub Stanford Linac Center (SLAC), uas kav tsuas yog ib billionth ntawm ib tug thib ob (attosecond), ionize lub core electrons thiab "kick" tawm ntawm qhov zoo siab molecule.
Txhawm rau txheeb xyuas qhov chaw ntawm cov hluav taws xob tso tawm no, lawv siv tus kheej zoo siablaser pulsesntsuas lub sij hawm emission ntawm cov electrons nyob rau hauv ntau cov lus qhia. Txoj kev no tau tso cai rau lawv kom raug xam qhov sib txawv ntawm qhov sib txawv ntawm lub sijhawm sib txawv los ntawm kev sib cuam tshuam ntawm cov hluav taws xob, lees tias qhov ncua sij hawm tuaj yeem ncav cuag 700 attoseconds. Nws yog ib qho tsim nyog sau cia tias qhov kev tshawb pom no tsis tsuas yog siv tau qee qhov kev xav yav dhau los, tab sis kuj tsim cov lus nug tshiab, ua rau cov kev xav cuam tshuam yuav tsum tau rov tshuaj xyuas thiab kho dua tshiab.
Tsis tas li ntawd, txoj kev tshawb fawb qhia txog qhov tseem ceeb ntawm kev ntsuas thiab txhais cov sij hawm ncua sij hawm, uas yog qhov tseem ceeb rau kev nkag siab txog cov txiaj ntsig ntawm kev sim. Hauv cov protein crystallography, kev kho mob duab, thiab lwm yam kev siv tseem ceeb uas cuam tshuam nrog kev cuam tshuam ntawm X-rays nrog teeb meem, cov ntaub ntawv no yuav yog lub hauv paus tseem ceeb rau kev ua kom zoo dua cov txheej txheem thiab txhim kho cov duab zoo. Yog li ntawd, pab neeg no npaj mus txuas ntxiv mus tshawb nrhiav cov hluav taws xob hluav taws xob ntawm ntau hom molecules txhawm rau nthuav tawm cov ntaub ntawv tshiab txog kev coj tus cwj pwm hluav taws xob hauv ntau lub tshuab thiab lawv cov kev sib raug zoo nrog cov qauv molecular, nteg cov ntaub ntawv ntau lub hauv paus rau kev txhim kho cov cuab yeej muaj feem xyuam. yav tom ntej.
Post lub sij hawm: Sep-24-2024