Brüggemann J, Weiss S, Nalbach P, Thorwart M. Cooling a magnetic nanoisland by spin-polarized currents.
PHYSICAL REVIEW LETTERS 2014;
113:076602. [PMID:
25170723 DOI:
10.1103/physrevlett.113.076602]
[Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Indexed: 06/03/2023]
Abstract
We investigate cooling of a vibrational mode of a magnetic quantum dot by a spin-polarized tunneling charge current exploiting the magnetomechanical coupling. The spin-polarized current polarizes the magnetic nanoisland, thereby lowering its magnetic energy. At the same time, Ohmic heating increases the vibrational energy. A small magnetomechanical 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 magnetomechanical coupling. The cooling rate increases at first with the magnetomechanical coupling and then saturates.
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