Spin effect on the low-temperature resistivity maximum in a strongly interacting 2D electron system

TL;DR

This study investigates how spin polarization affects the temperature at which resistivity peaks in a strongly interacting 2D electron system, revealing behavior that current theories cannot explain and highlighting the spin's role in electronic transport.

Contribution

It demonstrates the spin-dependent suppression of the resistivity maximum temperature in a strongly interacting 2D electron system, challenging existing theoretical models.

Findings

Resistivity shows a maximum near the renormalized Fermi temperature.

In spin-polarizing magnetic fields, the maximum temperature decreases significantly.

Current theories do not account for the observed spin-related behavior.

Abstract

The increase in the resistivity with decreasing temperature followed by a drop by more than one order of magnitude is observed on the metallic side near the zero-magnetic-field metal-insulator transition in a strongly interacting two-dimensional electron system in ultra-clean SiGe/Si/SiGe quantum wells. We find that the temperature $T_{\text{max}}$, at which the resistivity exhibits a maximum, is close to the renormalized Fermi temperature. However, rather than increasing along with the Fermi temperature, the value $T_{\text{max}}$ decreases appreciably for spinless electrons in spin-polarizing (parallel) magnetic fields. The observed behaviour of $T_{\text{max}}$ cannot be described by existing theories. The results indicate the spin-related origin of the effect.