Competing effects of interactions and spin-orbit coupling in a quantum wire

Area of Science:

• Condensed Matter Physics
• Quantum Mechanics

Background:

• Electron-electron interactions significantly influence electronic properties in low-dimensional systems.
• Rashba spin-orbit coupling (SOC) is crucial for spintronic devices, enabling spin manipulation via electric fields.

Purpose of the Study:

• Investigate the combined effects of electron-electron interactions and Rashba SOC in one-dimensional (1D) ballistic wires.
• Determine phase diagrams and identify parameter regimes governing the system's behavior.
• Analyze implications for spintronic device operation, specifically the Datta-Das transistor.

Main Methods:

• Renormalization group (RG) approach to analyze interacting electron systems.
• Construction of a phase diagram based on key parameters: Rashba coupling, Tomonaga-Luttinger (TL) stiffness, and backward scattering strength.

Main Results:

• Identification of parameter regimes leading to a dynamically generated spin gap.
• Characterization of the Luttinger liquid phase and its prevalence.
• Mapping of distinct electronic phases based on interaction and SOC strengths.

Conclusions:

• The interplay between electron-electron interactions and Rashba SOC dictates the electronic phase of 1D wires.
• Specific regimes favor a spin-gapped state, crucial for spin control, while others support a Luttinger liquid.
• Understanding these phases is essential for optimizing the performance of spintronic devices like the Datta-Das transistor.