Electron-electron drag in crystals with a multi-valley band. Magnetoresistivity and Hall-effect

Abstract

Hall-effect and magnetoresistivity of electrons in multi-valley bands of Si and Ge is considered with due regard for direct intervalley drag. Search of contribution of this drag shows that this interactioin sufficiently changes both effects. Calculated here values substantially differ from consequent those obtained on the base of popular approximation.

Influence of electron-electron drag on piezoresistance of n-Si

“…In Refs [1,2] it was presented the set of balance equations obtained as a first momentum of quantum kinetic equations:…”

“…The screening plays a significant, even appointing role in the area of small transferred vectors q ; therefore instead of ) ( 2 0 q q r we can use the following expression (see Ref. [1]):…”

“…are (see [2,3] and Eqs. (6) and (7)): For quasielastic collisions we have the form (see [1]) 1) and (13) one obtains the system of equations for partial drift velocities:…”

“…There the conductivity of crystal can be essentially influenced by mutual drag of carriers, which belong to different partial bands or valleys (see Refs. [1,2]). In particular, the inter-valley drag can sufficiently diminish electron mobility of n-Si and n-Ge at low temperatures.…”

Influence of mutual drag of light and heavy holes on conductivity of p-silicon and p-germanium

“…In contrast to crystals with one simple band, where the electron-electron scattering does not change total momentum of carriers, in multyvalley crystals the conductivity can be essentially influenced by mutual drag of carriers, which belong to different valleys (see Refs. [1,2]). The analogous effect has to appear in semiconductors where band carriers occupy several subbands and transitions between these subbands are sufficiently rare.…”