A Quantitative Analysis of the Pinch Effect in n-Type InSb

Abstract

A quantitative analysis of the pinch effect in an InSb has been carried out with the aid of two original experimental techniques. Firstly, an intrinsic Hall effect was utilized to measure the electron mobility in the pinched column. Secondly, the effective dimensions of the pinch channel were estimated from measurements of sample inductance. These techniques make it possible to investigate various aspects of the pinch effect in a semi-quantitative fashion. The steady-state density in the pinched column, as an example, is compared with a theory of isothermal pinching. Reasonably good agreement between the theory and experimental results were obtained, indicating that the electron temperature within the pinch remains nearly constant during the pinching process. The carrier density in the pinched column was found to saturate at about 10¹⁷ cm⁻³. As one explanation, population inversion between the states in the bottom of the conduction band and in the top of the valence band is considered.