Response to Parallel Magnetic Field of a Dilute 2D Electron System across the Metal-Insulator Transition

TL;DR

This study investigates how a parallel magnetic field affects the resistivity of a very dilute insulating 2D electron system in silicon MOSFETs, revealing unexpected saturation behavior similar to that in conducting states near the metal-insulator transition.

Contribution

It demonstrates that the resistivity response to magnetic fields in dilute insulating 2D electron systems exhibits saturation behavior, a phenomenon previously observed only in conducting states.

Findings

Resistivity increases sharply with magnetic field then saturates.

Saturation occurs at about one Tesla magnetic field.

Behavior is similar to that in the conducting side of the transition.

Abstract

The response to a parallel magnetic field of the very dilute insulating two-dimensional system of electrons in silicon MOSFET's is dramatic and similar to that found on the conducting side of the metal-insulator transition: there is a large initial increase in resistivity with increasing field, followed by saturation to a value that is approximately constant above a characteristic magnetic field of about one Tesla. This is unexpected behavior in an insulator that exhibits Efros-Shklovskii variable-range hopping in zero field, and appears to be a general feature of very dilute electron systems.