Mene ne Hall sakamako

Idan ka tambaye wani mutum saba da kimiyyar lissafi a kan matakin da wani asali sanin abin da wani Hall sakamako da kuma inda shi ne amfani da, ba za ka iya samun amsa. Abin mamaki, a cikin hakikar da na zamani a duniya wannan ya faru quite sau da yawa. A gaskiya ma, cikin Hall sakamako da ake amfani a da yawa lantarki na'urorin. Alal misali, da zarar wani m kwamfuta floppy faifai tafiyarwa kayyade farko matsayi na mota ta amfani da Hall janareto. Dace na'urori masu auna sigina suna "koma" da kuma a cikin makirci na zamani tafiyarwa domin CDs (duka CD, da kuma DVD). Bugu da ƙari kuma, aikace-aikace sun hada da ba wai kawai daban-daban ma'auni kida, amma ko da wutar lantarki janareto dangane da canji na zafi zuwa rafi na cajin barbashi da wani Magnetic filin (MHD).

Edwin Herbert Hall a 1879 shekara, gudanar da gwaje-gwajen da conductive farantin, wanton samu da farko wurin, m faru na wani sabon abu (danniya) a cikin hulda da lantarki da kuma Magnetic filin. Amma da farko abubuwan da farko.

Bari mu yi kadan tunani gwaji: dauki wani farantin karfe da kuma ratsa shi lantarki a halin yanzu. Next, sanya shi a cikin wani waje da halin maganaɗisu filin haka cewa Lines na filin ƙarfi suna daidaitacce perpendicular da jirgin saman na conductive farantin. A sakamakon haka, da fuskoki (fadin shugabanci na yanzu), wani m bambanci. Wannan ne Hall sakamako. Dalilin da ya faru da aka sani Lorentz karfi.

Akwai wata hanya domin sanin darajar da resultant ƙarfin lantarki (wani lokacin kira Hall m). A general magana daukan siffar:

Uh = Eh * H,

inda H - farantin kauri. Eh - ƙarfi daga cikin waje filin.

Tun da m ne saboda redistribution na cajin yan dako a cikin shugaba, shi yana da iyaka (da tsari ba dore har abada). Kaikaice yunkuri na cajin zai daina a daidai lokacin da tamanin da Lorentz karfi (F = q * v * B) danganta adawa q * Eh (q - cajin).

Tun da na yanzu yawa J ne daidaita da samfurin na cajin yawa, su gudu da mutum dabi'u na q, Ina nufin

J = n * q * v,

bi da bi,

v = J / (q * n).

Saboda haka (haxe dabara da tsanani):

Eh = B * (J / (q * n)).

Hada duk na sama da kuma sanin da m na cikin zauren ta hanyar da darajar da cajin:

Uh = (J * B * H) / n * q).

Hall sakamako ya nuna cewa, wani lokacin a karafa ba ya lura electron da rami madugu. Alal misali, shi ne cadmium, beryllium, kuma tutiya. Karatu Hall sakamako a semiconductors, babu shakka cewa cajin yan dako - da "rami". Duk da haka, kamar yadda riga ya nuna, shi ne kuma m zuwa karafa. An yi imani da cewa a lokacin da cajin rarraba (samuwar zauren ginin) kowa vector aka kafa ta electrons (korau alamar). Duk da haka, shi ya juya daga cewa filin na yanzu ba ya haifar da electrons. A aikace, wannan dukiya da ake amfani da sanin da yawa na cajin yan dako a cikin semiconducting abu.

Babu kasa da aka sani jimla Hall sakamako (1982). Yana wakiltar daya daga cikin kaddarorin da biyu-girma electron gas madugu (barbashi su kyauta motsa a kawai biyu kwatance) a karkashin yanayi na musamman low yanayin zafi da kuma high waje Magnetic filayen. wanzuwar "fragmentation" da aka gano a lokacin da karatu da sakamako. Akwai wani ra'ayi da cewa cajin ba kafa ta guda dako (1 + 1 + 1), da kuma gyara daga (1 + 1 + 0.5). Duk da haka, shi ya juya fitar da cewa babu dokokin sun karye. A daidai da Pauli manufa, a kusa da kowane electron a wani Magnetic filin da aka halitta da wani irin haskoki na vortex kwarara. Tare da kara filin tsanani halin da ake ciki taso idan matching "= daya daya electron vortex" daina zama gamsu. Kowane barbashi da mahara kamfani mai suna Quanta na Magnetic juyi. Wadannan sabon barbashi ne daidai da hanyar da fractional sakamakon lokacin da Hall sakamako.