Quantum dynamics of molecular magnets in ultra-fast sweeping magnetic fields

Abstract

Non-equilibrium magnetization process of a S= 1 2 spin triangle in molecular magnet V 15 has been studied by using fast sweeping pulsed magnetic fields. In the up sweep, the magnetization jump of about 1 μ B is found at the level crossing between the ground S= 1 2 and the excited S= 3 2 states, while it is about 2 μ B in the down sweep. The jump in the up sweep is half of that expected in the equilibrium magnetization process. This phenomenon is interpreted by considering the difference of mixing in two degenerated S= 1 2 states with the S= 3 2 state.