Kev Tshawb Fawb Tunneling Electron Microscope Applications
Lub hauv paus ntsiab lus ntawm tunneling microscopy yog ua kom ntse siv cov nyhuv tunneling thiab tunneling tam sim no hauv physics. Muaj ntau tus "dawb" electrons nyob rau hauv lub cev hlau, cov "dawb" electrons nyob rau hauv cov hlau lub cev ntawm lub zog faib yog concentrated nyob rau hauv ib ncig ntawm lub Fermi zog theem, thaum nyob rau hauv cov hlau ciam teb muaj ib tug siab zog tshaj. Fermi zog theem ntawm lub peev xwm barrier. Yog li ntawd, los ntawm qhov kev xav ntawm classical physics, lub "dawb" electrons nyob rau hauv cov hlau, tsuas yog lub zog siab tshaj lub ciam teb muaj peev xwm barrier ntawm cov electrons yuav khiav tawm ntawm cov hlau mus rau sab nraud. Txawm li cas los xij, raws li quantum mechanics, cov hluav taws xob dawb hauv cov hlau kuj muaj qhov tsis muaj zog, thiab thaum cov hluav taws xob nthwv dej no nthuav tawm mus rau thaj tsam hlau thiab ntsib qhov cuam tshuam ntawm qhov chaw, yuav muaj qee qhov kev sib kis. Qhov ntawd yog hais tias, yuav muaj ib feem ntawm lub zog hauv qab qhov chaw muaj peev xwm barrier ntawm lub tshuab hluav taws xob tuaj yeem nkag mus rau cov hlau nto thaiv, tsim cov hlau nto "electron cloud". Cov nyhuv no yog hu ua tunneling effect. Yog li ntawd, thaum ob lub hlau nyob sib ze heev (hauv qab ob peb nanometers), cov huab cua hluav taws xob ntawm ob lub hlau yuav nkag mus rau ib leeg. Thaum qhov tsim nyog voltage ntxiv, txawm tias ob lub hlau tsis sib txuas tiag tiag, yuav muaj qhov tam sim no ntws los ntawm ib qho hlau mus rau lwm qhov, uas yog hu ua qhov tam sim no.
Qhov tam sim no thiab qhov av tsis kam nrog qhov qhov sib txawv yog qhov nkag siab zoo rau cov kev hloov hauv qhov sib txawv, txawm tias tsuas yog 0.01nm hloov, kuj tuaj yeem ua rau muaj kev hloov pauv tseem ceeb hauv qhov tam sim no.
Yog hais tias ib tug ntse sojntsuam (xws li tungsten koob) nyob rau hauv qhov kev ncua deb ntawm tus du nto ntawm tus qauv ob peb feem kaum ntawm ib nanometer qhov siab thaum uas tig mus rau saum npoo nyob rau hauv lub x, y kev taw qhia scanning, vim hais tias txhua atom muaj ib tug tej yam me me, thiab yog li ntawd. nyob rau hauv cov txheej txheem scanning qhov sib txawv yuav nrog cov x, y ntawm qhov sib txawv thiab txawv, qhov tunneling tam sim no ntws los ntawm kev sojntsuam kuj txawv. Txawm tias qhov siab hloov ntawm ob peb feem pua ntawm ib nanometer tuaj yeem cuam tshuam rau hauv qhov tunneling tam sim no. Kev siv lub scanning sojntsuam nrog lub synchronized recorder, qhov kev hloov pauv tam sim no yuav raug kaw, koj tuaj yeem tau txais qhov kev daws teeb meem ntawm ob peb nanometers ntawm scanning tunneling electron microscope dluab.
