Magnetic effects on1fnoise inn-InSb

$\frac{1}{f}$ noise has been observed in resistors fabricated from high-purity single-crystal $n$-InSb at 75 K. Noise levels which are much smaller than predicted by the Hooge relation are routinely observed. The $\frac{1}{f}$ noise is extremely sensitive to an applied magnetic field which is perpendicular to the current. A field of 24 kG increases the fractional noise, $\frac{S_V}{V^2}$, by a factor of ${10}^2$ to ${10}^4$. These large effects nearly vanish when the magnetic field is parallel to the current. Similar effects are observed for $\frac{1}{f}$ noise present in the Hall voltage. The data display a lack of reproducibility from sample to sample and with surface treatment within the same sample.