Berlin 2015 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
TT: Fachverband Tiefe Temperaturen
TT 26: Quantum Dynamics, Decoherence and Quantum Information (jointly with DY)
TT 26.1: Talk
Monday, March 16, 2015, 15:00–15:15, BH-N 334
Cooling a Magnetic Nanoisland by Spin-Polarized Currents — •Peter Nalbach1, Jochen Brüggemann1, Stephan Weiss2, and Michael Thorwart1 — 1I. Institut für Theoretische Physik, Universität Hamburg, Germany — 2Theoretische Physik, Universität Duisburg-Essen and CENIDE, Germany
We investigate cooling of a vibrational mode of a magnetic quantum dot by a spin-polarized tunnelling charge current exploiting the magneto-mechanical coupling. The spin-polarized current polarizes the magnetic nano-island, thereby lowering its magnetic energy. At the same time, Ohmic heating increases the vibrational energy. A small magneto-mechanical coupling then permits us to remove energy from the vibrational motion and cooling is possible. We find a reduction of the vibrational energy below 50% of its equilibrium value. The lowest vibration temperature is achieved for a weak electron-vibration coupling and a comparable magneto-mechanical coupling. The cooling rate increases at first with the magneto-mechanical coupling and then saturates.
see: Phys. Rev. Lett. 113, 076602 (2014).