Phonon-assisted tunneling in the quantum regime of Mn12 acetate

Abstract

The effects of spin and phonon baths were explored. As part of this study, the magnetization of a small single crystal of Mn12-ac in high fields and at sub-Kelvin temperatures was obtained from magnetic torque experiments. For this crystal, it was shown that the transition between coherent tunneling on the ground state and on upper state takes place, level after level, when they come into coincidence in an applied sweeping field.