Suppression of Spin Dephasing in a Two-Dimensional Electron Gas with a Quantum Point Contact

TL;DR

Introducing a quantum point contact in a two-dimensional electron gas significantly suppresses spin dephasing across the entire system, enabling improved electrical control of spin states via spin-orbit coupling.

Contribution

This study demonstrates that a quantum point contact can suppress spin dephasing in a 2D electron gas, extending the effect beyond the contact region.

Findings

Spin dephasing is suppressed throughout the 2D electron gas.

Quantum point contact enables electrical control of spin states.

Suppression effect is not limited to the contact vicinity.

Abstract

Spin-orbit coupling is a source of strong spin dephasing in two- and three-dimensional semiconducting systems. We report that spin dephasing in a two-dimensional electron gas can be suppressed by introducing a quantum point contact. Surprisingly, this suppression was not limited to the vicinity of the contact but extended to the entire two-dimensional electron gas. This facilitates the electrical control of the spin degree of freedom in a two-dimensional electron gas through spin-orbit coupling.