Feb 20 – 25, 2017
Fairmont Chateau Lake Louise
Canada/Mountain timezone

Quantum Einstein de Haas Effect Studied With Molecular Spintronic Devices

Feb 21, 2017, 10:48 AM
36m
Mount Temple A (Fairmont Chateau Lake Louise)

Mount Temple A

Fairmont Chateau Lake Louise

Lake Louise, AB, CANADA
Invited Talk

Speaker

Franck Balestro (Institut Néel, CNRS, Grenoble Alpes University, BP 166, 38042 Grenoble, France)

Description

One hundred years ago it has been discovered that a change of magnetization in a macroscopic magnetic object results in a mechanical rotation of this magnet [1]. The effect, known as Einstein de Haas or Richardson effect, demonstrates that a spin angular momentum in the magnet compensates for the mechanical angular momentum associated with its rotation. The experiment is therefore a macroscopic manifestation of the conservation of total angular momentum and energy in electronic spins. According to Noether's theorem, conservation of angular momentum follows from a system`s rotational invariance and would be valid for the ensemble of spins in a macroscopic ferromagnet as well as for an individual spin. It has been recently proposed that single spin systems would therefore manifest an Einstein de Haas effect at the quantum level [2].
Here we propose the first experimental realization of a quantum Einstein-de Haas experiment and describe a macroscopic manifestation of the conservation of total angular momentum in individual spins, using a single molecule magnet coupled to a nanomechanical resonator. We demonstrate that the spin associated with the single molecule magnet is then subject to conservation of total angular momentum and energy which results in a total suppression of the molecule’s quantum tunneling of magnetization [3].

  1. A. Einstein and W.J. de Haas, Deutsche Physikalische Gesellschaft, Verhandlungen, 1915, 17, 152.
  2. E. M. Chudnovsky and D. A. Garanin, Phys. Rev. Lett., 1994, 72, 3433; Phys. Rev. B, 2010, 81, 214423; Phys. Rev. B, 2005 72, 094426;
 Phys. Rev. X, 2011, 1, 011005.
  3. M. Ganzhorn, S. Klyatskaya, M. Ruben, W. Wernsdorfer, Nature Nanotechnol., 2013, 8, 165; Nature Comm., 2016.

Primary authors

Marc Ganzhorn (Institut Néel, CNRS, Grenoble Alpes University, BP 166, 38042 Grenoble, France) Svetlana Klyatskaya (Institut of Nanotechnology (INT), Karlsruhe Institute of Technology (KIT), 76344 Eggenstein-Leopoldshafen, Germany) Mario Ruben (Institut of Nanotechnology (INT), Karlsruhe Institute of Technology (KIT), 76344 Eggenstein-Leopoldshafen, Germany) Franck Balestro (Institut Néel, CNRS, Grenoble Alpes University, BP 166, 38042 Grenoble, France) Wolfgang Wernsdorfer (Institut of Nanotechnology (INT), Karlsruhe Institute of Technology (KIT), 76344 Eggenstein-Leopoldshafen, Germany)

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