Voltage induced conversion of helical to uniform nuclear spin polarization in a quantum wire

Abstract

We study the effect of bias voltage on the nuclear spin polarization of a ballistic wire, which contains electrons and nuclei interacting via hyperfine interaction. In equilibrium, the localized nuclear spins are helically polarized due to the electron-mediated Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction. Focusing here on non-equilibrium, we find that an applied bias voltage induces a uniform polarization, from both helically polarized and unpolarized spins available for spin flips. Once a macroscopic uniform polarization in the nuclei is established, the nuclear spin helix rotates with frequency proportional to the uniform polarization. The uniform nuclear spin polarization monotonically increases as a function of both voltage and temperature, reflecting a thermal activation behavior. Our predictions offer specific ways to test experimentally the presence of a nuclear spin helix polarization in semiconducting quantum wires.

8 pages, 4 figures

References in corpus (12)

• Microscopic approach to current-driven domain wall dynamics
• Prospects for Spin-Based Quantum Computing
• Kondo effect in the helical edge liquid of the quantum spin Hall state
• Proton magnetic resonance imaging with a nitrogen-vacancy spin sensor
• Nuclear Magnetism and Electronic Order in 13C Nanotubes
• Magnetic Ordering of Nuclear Spins in an Interacting 2D Electron Gas
• Helical edge states coupled to a spin bath: Current-induced magnetization
• Helical nuclear spin order in a strip of stripes in the Quantum Hall regime
• Boundary between the thermal and statistical polarization regimes in a nuclear spin ensemble
• Dynamic nuclear polarization from current-induced electron spin polarization
• Nuclear Spin Relaxation in Rashba Nanowires
• NMR Response of Nuclear Spin Helix in Quantum Wires with Hyperfine and Spin-Orbit Interaction