HotCarrier Magnetoresistance
Abstract
The characteristics of hotcarrier magnetoresistance for small magnetic fields are studied with the assumptions: (a) The constantenergy surfaces are spherical and carriers are scattered by acoustic and optical phonons; and (b) the constantenergy surfaces are ellipsoidal and the scattering is due to acoustic, optical, and intervalley phonons. It is shown that for a spherical constantenergysurface model the magnetoresistance has a small negative value decreasing with increasing field, and the magnetoresistance coefficient is independent of the field if the scattering is by acoustic phonons alone. On the other hand, for predominant opticalphonon scattering the magnetoresistance and also the magnetoresistance coefficient are positive and decrease with increasing field. In the case of manyvalley band structure as in ntype germanium, the characteristics of magnetoresistance and magnetoresistance coefficient for predominant acousticphonon scattering are the same as for a spherical constantenergysurface model, but the sign is positive and the values are larger. The variation of magnetoresistance and magnetoresistance coefficient for predominant opticalphonon scattering when the electric field is in the [100] direction is similar to that for a spherical constantenergysurface model, but the values are higher and the characteristic varies in details. For the [111] direction of the field, on the other hand, the magnetoresistance decreases with the field, but the magnetoresistance coefficient increases with the field. The values of magnetoresistance calculated from theory, assuming acoustic and opticalphonon scattering, are found to agree closely with the experimental results. The inclusion of the effects of intervalley scattering leads to a further improvement in the agreement.
 Publication:

Physical Review
 Pub Date:
 October 1966
 DOI:
 10.1103/PhysRev.150.632
 Bibcode:
 1966PhRv..150..632N