Spin-phonon interaction induces tunnel splitting in single-molecule magnets

Abstract

Quantum tunneling of the magnetization is a major obstacle to the use of single-molecule magnets (SMMs) as basic constituents of next-generation storage devices. In this context, phonons are often only considered (perturbatively) as disturbances that promote the spin system to traverse the anisotropy barrier. Here, we demonstrate the ability of phonons to induce a tunnel splitting of the ground doublet which then reduces the required bistability due to Landau-Zener tunneling of the magnetization. Harmful are those phonons that modify the spin Hamiltonian so that its rotational symmetry about the field axis is destroyed. In our calculations we treat spins and phonons on the same footing by performing quantum calculations of a Hamiltonian where the single-anisotropy tensors are coupled to harmonic oscillators.

arXiv comment6 pages, 7 figures, submitted

References in corpus (7)

• Butterfly hysteresis loop and dissipative spin reversal in the S=1/2, V15 molecular complex
• Spin Tunneling and Phonon-assisted Relaxation in Mn12-acetate
• Universal mechanism of spin relaxation in solids
• Landau Zener method to study quantum phase interference of Fe8 molecular nanomagnets
• Phonon-assisted tunneling in the quantum regime of Mn12-ac
• Spin-Peierls instabilities of antiferromagnetic rings in a magnetic field
• Dynamic spin Jahn-Teller effect in small magnetic clusters

Cited by in corpus (3)

• Vibronic effects on the quantum tunnelling of magnetisation in Kramers single-molecule magnets
• Toroidal magnetic molecules stripped to their basics
• Supersymmetric spin-phonon coupling prevents odd integer spins from quantum tunneling