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On Ground State Tunneling in Mn$_{12}$-Acetate

K. M. Mertes·M. P. Sarachik·Y. Paltiel·H. Shtrikman·E. Zeldov·E. M. Rumberger·D. N. Hendrickson·G. Christou
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Abstract

We report Hall sensor measurements of the magnetic relaxation of Mn$_{12}$-acetate as a function of magnetic field applied along the easy axis of magnetization for a series of closely-spaced temperatures between 0.24 K and 1.9 K. We map out a region in the $H-T$ plane where ground state tunneling is observed, a region where tunneling proceeds via thermally-assisted tunneling, and a crossover region where both participate in the relaxation. We observe the occasional absence of ground-state tunneling under conditions where one would expect it to be present, and suggest a resolution to the enigma.

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K. M. Mertes, M. P. Sarachik, Y. Paltiel, H. Shtrikman, E. Zeldov, E. M. Rumberger, D. N. Hendrickson, G. Christou. 2001-08-16. On Ground State Tunneling in Mn$_{12}$-Acetate. https://doi.org/10.1103/physrevb.65.212401

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