Qhov sib txawv tseem ceeb ntawm Hall effect thiab quantum Hall nyhuv yog tias Hall nyhuv feem ntau tshwm sim ntawm semiconductors, whereas lub quantum Hall nyhuv tshwm sim nyob rau hauv cov hlau.
Hall effect yog hais txog lub cim ntawm ib qho hluav taws xob muaj peev xwm perpendicular rau ob qho tib si hluav taws xob tam sim no ntws raws cov khoom siv thiab cov khoom sib nqus sab nraud siv ntawm lub kaum sab xis mus rau tam sim no raws li daim ntawv thov ntawm magnetic teb. Cov nyhuv no tau pom nyob rau xyoo 1879 los ntawm Edwin Hall. Cov nyhuv quantum Hall tau pom tom qab, raws li kev muab los ntawm Hall effect.
Hall Effect yog dab tsi?
Hall effect yog hais txog kev tsim cov hluav taws xob sib txawv uas hloov mus rau qhov hluav taws xob tam sim no thiab mus rau qhov chaw sib nqus. Ntawm no, qhov sib txawv voltage tshwm sim nyob rau hauv ib qho hluav taws xob conductor. Cov hluav taws xob tam sim no yog tsim los ntawm cov khoom siv hluav taws xob no thiab cov hlau nplaum siv rau nws yog perpendicular rau tam sim no. Cov nyhuv no tau tshawb pom los ntawm Edwin Hall hauv xyoo 1879. Nws kuj tau tsim lub Hall coefficient, uas yog qhov piv ntawm qhov induced hluav taws xob teb rau cov khoom ntawm qhov ceev tam sim no thiab siv magnetic teb. Tus nqi ntawm cov coefficient no yog cov yam ntxwv ntawm cov khoom uas tus neeg xyuas pib ua. Yog li ntawd, tus nqi ntawm cov coefficient no nyob ntawm hom, tus lej thiab cov khoom ntawm tus nqi thauj khoom uas ua rau tam sim no.
Hall effect tshwm sim vim qhov xwm txheej tam sim no hauv tus neeg xyuas pib. Feem ntau, ib qho hluav taws xob tam sim no muaj qhov txav ntawm ntau cov khoom siv me me xws li electrons, qhov, ions lossis tag nrho peb ntawm lawv. Thaum muaj ib qho chaw sib nqus, cov nqi no yuav muaj lub zog hu ua Lorentz force. Thaum tsis muaj qhov sib nqus zoo li no, cov nqi them yuav ua raws li ib txoj kab ncaj nraim ntawm kev pom ntawm kev sib tsoo nrog impurities.
Tsis tas li ntawd, thaum lub teb sib nqus siv perpendicularly, txoj kev ntawm kev sib tsoo ntawm kev sib tsoo zoo li nkhaus; Yog li, cov nqi txav mus los sib sau ua ke ntawm ib lub ntsej muag ntawm cov khoom, tawm hauv qhov sib npaug thiab cov nqi sib txawv ntawm lwm lub ntsej muag. Cov txheej txheem no ua rau muaj kev faib tawm asymmetric ntawm kev them nqi ceev thoob plaws Hall lub caij uas tshwm sim los ntawm lub zog uas yog perpendicular rau ob qho tib si ntawm txoj kev pom thiab daim ntawv thov sib nqus. Kev sib cais ntawm cov nqi no tsim kom muaj hluav taws xob. Qhov no hu ua Hall effect.
Quantum Hall Effect yog dab tsi?
Quantum Hall nyhuv yog lub tswv yim quantum mechanical uas tshwm sim hauv 2D electron system uas raug rau qhov kub thiab txias thiab muaj zog sib nqus. Ntawm no, "Hall conductance" tau dhau los ntawm quantum Hall kev hloov pauv kom coj mus rau qhov muaj nuj nqis ntawm ib qib. Kev qhia lej rau cov nyhuv quantum yog raws li hauv qab no:
Hall conductance=Ichannel/VHall=v.e2/h
Ichannel yog channel tam sim no, VHall yog Hall voltage, e yog tus nqi qis, h yog Plank qhov tas li thiab v yog ib qho prefactor hu ua qhov ua kom tiav uas yog tus nqi sib npaug lossis tus nqi feem. Yog li ntawd, peb tuaj yeem txheeb xyuas tau tias cov txiaj ntsig ntawm quantum yog qhov sib npaug ntawm cov zauv feem ntawm quantum Hall nyhuv nyob ntawm seb "v" yog tus lej lossis feem, feem.
Cov txiaj ntsig quantum Hall muaj ib qho tshwj xeeb, uas yog, qhov kev pheej hmoo ntawm quantization raws li cov hluav taws xob ceev sib txawv. Ntawm no, qhov ceev ntawm electron tseem nyob tas li thaum Fermi qib nyob hauv qhov sib txawv ntawm qhov huv si; Yog li, qhov xwm txheej no sib raug rau ib qho uas cov qib fermi yog lub zog nrog lub xeev qhov ntom ntom, txawm tias cov xeev no nyob hauv cheeb tsam. Thaum txiav txim siab qhov feem ntawm quantum Hall cov nyhuv, nws nyuaj dua vim tias nws lub neej vam khom los ntawm kev sib cuam tshuam ntawm electron-electron.
Qhov txawv ntawm Hall Effect thiab Quantum Hall Effect yog dab tsi?
Qhov sib txawv tseem ceeb ntawm Hall effect thiab quantum Hall effect yog tias Hall effect feem ntau tshwm sim ntawm cov khoom siv hluav taws xob, thaum lub quantum Hall nyhuv tshwm sim hauv cov hlau. Lwm qhov sib txawv tseem ceeb ntawm Hall effect thiab quantum Hall effect yog tias Hall effect tshwm sim qhov twg muaj qhov tsis muaj zog sib nqus thiab nruab nrab kub thaum Quantum Hall effect yuav tsum muaj zog sib nqus thiab kub qis dua.
Hauv qab infographic qhia txog qhov sib txawv ntawm Hall effect thiab quantum Hall effect.
Summary – Hall Effect vs Quantum Hall Effect
Cov nyhuv quantum Hall yog muab los ntawm cov nyhuv Hall ntawm classical. Qhov sib txawv tseem ceeb ntawm Hall effect thiab quantum Hall nyhuv yog tias Hall nyhuv feem ntau tshwm sim ntawm semiconductors, whereas lub quantum Hall nyhuv tshwm sim nyob rau hauv cov hlau.
