Cooling a magnetic nanoisland by spin-polarized currents

Abstract

We investigate cooling of a vibrational mode of a magnetic quantum dot by a spin-polarized tunneling charge current, exploiting the interaction between the magnetization and the vibration. The spin-polarized charge current polarizes the magnetic nanoisland, lowering its energy. Inevitable Ohmic energy losses due to the charge current flow will heat up the vibration. A small but finite coupling between the vibration and the local magnetic moment then permits an energy exchange, resulting in a lower energy, i.e., cooling, of the vibrational mode. We determine parameter regimes for the cooling of the vibration below $50\%$ of its initial value. Lowest final phonon temperature is observed for weak electron-phonon-coupling but similar magnetization-phonon coupling strength. The cooling rate, thereby, increases at first with the magnetization-phonon coupling and then saturates.

5 pages, 5 figures

References in corpus (6)

• Vibrational sidebands and dissipative tunneling in molecular transistors
• Micrometre-scale refrigerators
• Current-induced nonequilibrium vibrations in single-molecule devices
• Nanomechanical Analog of a Laser: Amplification of Mechanical Oscillations by Stimulated Zeeman Transitions
• Transport through quantum-dot spin valves containing magnetic impurities
• Macrospin Tunneling and Magnetopolaritons with Nanomechanical Interference

Cited by in corpus (8)

• Cooling by heating in nonequilibrium nanosystems
• Nonlinear chiral refrigerators
• Control of vibrational states by spin-polarized transport in a carbon nanotube resonator
• Cooling molecular electronic junctions by AC current
• Superconductor-quantum dot hybrid coolers
• Spin-vibronics in interacting nonmagnetic molecular nanojunctions
• Phase-controlled heat modulation with Aharonov-Bohm interferometers
• Antiresonant quantum transport in ac driven molecular nanojunctions