Thermoelectric unipolar spin battery in a suspended carbon nanotube

Abstract

A quantum dot formed in a suspended carbon nanotube exposed to an external magnetic field is predicted to act as a thermoelectric unipolar spin battery which generates pure spin current. The built-in spin flip mechanism is a consequence of the spin-vibration interaction resulting from the interplay between the intrinsic spin-orbit coupling and the vibrational modes of the suspended carbon nanotube. On the other hand, utilizing thermoelectric effect, the temperature difference between the electron and the thermal bath to which the vibrational modes are coupled provides the driving force. We find that both magnitude and direction of the generated pure spin current are dependent on the strength of spin-vibration interaction, the sublevel configuration in dot, the temperatures of electron and thermal bath, and the tunneling rate between the dot and the pole. Moreover, in the linear response regime, the kinetic coefficient is non-monotonic in the temperature $T$ and it reaches its maximum when $k_{B}T$ is about one phonon energy. The existence of a strong intradot Coulomb interaction is irrelevant for our spin battery, provided that high-order cotunneling processes are suppressed.

16 pages, 6 figures. Accepted by J. Phys.: Condens. Matter

References in corpus (11)

• Molecular Transport Junctions: Vibrational Effects
• Coupling of Spin and Orbital Motion of Electrons in Carbon Nanotubes
• Inelastic transport theory from first-principles: methodology and applications for nanoscale devices
• Electron Transport and Hot Phonons in Carbon Nanotubes
• Large spin-orbit coupling in carbon nanotubes
• Cooling carbon nanotubes to the phononic ground state with constant electron current
• Ground-state cooling of a carbon nanomechanical resonator by spin-polarized current
• Kondo effect in carbon nanotube quantum dots with spin-orbit coupling
• Generation of pure spin currents by superconducting proximity effect in quantum dots
• Control of vibrational states by spin-polarized transport in a carbon nanotube resonator
• Mesoscopic fluctuations of spin currents

Cited by in corpus (1)

• Performance of the T-matrix based master equation for Coulomb drag in double quantum dots