Suppression of Quantum Phase Interference in Molecular Magnets Fe₈ with Dipolar-Dipolar Interaction

Abstract

Renormalized tunnel splitting with a finite distribution in the biaxial spin model for molecular magnets is obtained by taking into account the dipolar interaction of enviromental spins. Oscillation of the resonant tunnel splitting with a transverse magnetic field along the hard axis is smeared by the finite distribution which subsequently affects the quantum steps of hysteresis curve evaluated in terms of the modified Landau-Zener model of spin flipping induced by the sweeping field. We conclude that the dipolar-dipolar interaction drives decoherence of quantum tunnelling in molcular magnets Fe₈, which explains why the quenching points of tunnel spliting between odd and even resonant tunnelling predcited theoretically were not observed experimentally.

5 pages including 3 figure and 1 table. To appear in Physical Review B

References in corpus (4)

• Spin tunneling via dislocations in Mn-12 acetate crystals
• Dislocation-induced spin tunneling in Mn-12 acetate
• Quantum Step Heights in Hysteresis Loops of Molecular Magnets
• Proton Spin Relaxation Induced by Quantum Tunneling in Fe8 Molecular Nanomagnet

Cited by in corpus (3)

• Quantum tunneling of two coupled single-molecular magnets
• Non-exponential relaxation and quantum tunnel splitting in molecular magnet Fe8
• Dynamical Monte Carlo investigation of spin reversals and nonequilibrium magnetization of single-molecule magnets