Structure in the flicker-noise power spectrum of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>n</mml:mi></mml:math>-InSb

Abstract

We have measured the power spectrum of flicker noise in high-purity, single-crystal $n$-InSb at 76 K in the frequency range 0.1 Hz-10 kHz. The power spectrum can be interpreted as a superposition of two noise spectra. One of them is $\frac{1}{f}$ like at frequencies above a cutoff frequency ${f}_{0}$ which is on the order of a few hundred Hz, while at frequencies below ${f}_{0}$ it appears to level off to a constant value. The second spectrum is dominant at frequencies well below ${f}_{0}$ and behaves as $\frac{1}{f}$. Noise power much smaller than that predicted by the Hooge relation, ${S}_{\ensuremath{\delta}V}=\frac{\ensuremath{\alpha}{V}^{2}}{\mathrm{NF}}$, is observed. Also it is found that chemical treatments of the surface have a strong influence on the magnitude of the measured flicker noise.