Direct experimental observation of the Hall angle in the low-temperature breakdown regime of n-GaAs

Using the technique of photoluminescence imaging during electrical transpor t in crossed electric and magnetic fields, the rotation of the current flow direction has been observed. The rotation angle is identically the Hall an gle. As a model system, a thin n-type GaAs layer in the regime of low-tempe rature impurity breakdown has been used, generating filamentary current pat terns. The measurement of the Hall angle allows one to determine the mobili ty inside current filaments. [S0163-1829(98)05043-7].