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Magnetic Anisotropy Variations and Non-Equilibrium Tunneling in a Cobalt Nanoparticle

M. M. Deshmukh·S. Gueron·E. Bonet·A. N. Pasupathy·S. Kleff·J. von Delft·D. C. Ralph
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Abstract

We present detailed measurements of the discrete electron-tunneling level spectrum within nanometer-scale cobalt particles as a function of magnetic field and gate voltage, in this way probing individual quantum many-body eigenstates inside ferromagnetic samples. Variations among the observed levels indicate that different quantum states within one particle are subject to different magnetic anisotropy energies. Gate-voltage studies demonstrate that the low-energy tunneling spectrum is affected dramatically by the presence of non-equilibrium spin excitations.

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M. M. Deshmukh, S. Gueron, E. Bonet, A. N. Pasupathy, S. Kleff, J. von Delft, D. C. Ralph. 2001-08-09. Magnetic Anisotropy Variations and Non-Equilibrium Tunneling in a Cobalt Nanoparticle. https://doi.org/10.1103/physrevlett.87.226801

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