# Metallic state in a strongly interacting spinless two-valley electron system in two dimensions

## TL;DR

This study demonstrates the persistence of metallic behavior in a strongly interacting, spinless two-valley 2D electron system in high-quality SiGe/Si/SiGe quantum wells, confirming a genuine metal-insulator transition independent of spin degrees of freedom.

## Contribution

It provides experimental evidence of a true metal-insulator transition in a spinless, two-valley 2D electron system, contrasting with earlier disordered samples.

## Key findings

- Metallic temperature dependence persists in spinless 2D systems.
- Genuine MIT confirmed in high-quality, strongly interacting 2D electron systems.
- Magnetic field-induced spin polarization does not eliminate metallic behavior.

## Abstract

We have studied the strongly interacting, two-valley two-dimensional (2D) electron system in ultrahigh mobility SiGe/Si/SiGe quantum wells in parallel magnetic fields strong enough to completely polarize the electron spins thus making the electron system "spinless". It occurs that the metallic temperature dependence of the resistivity, although weaker than that in the absence of magnetic field, still remains strong even when the spin degree of freedom is removed. Several independent methods have been used to establish the existence of the genuine MIT in the spinless two-valley 2D system. This is in contrast to the previous results obtained on more disordered silicon samples, where the polarizing magnetic field causes a complete quench of the metallic temperature behavior.