Chern Numbers for Spin Models of Transition Metal Nanomagnets

Abstract

We argue that ferromagnetic transition metal nanoparticles with fewer than approximately 100 atoms can be described by an effective Hamiltonian with a single giant spin degree of freedom. The total spin $S$ of the effective Hamiltonian is specified by a Berry curvature Chern number that characterizes the topologically non-trivial dependence of a nanoparticle's many-electron wavefunction on magnetization orientation. The Berry curvatures and associated Chern numbers have a complex dependence on spin-orbit coupling in the nanoparticle and influence the semiclassical Landau-Liftshitz equations that describe magnetization orientation dynamics.

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Cited by in corpus (10)

• Exponential localization of Wannier functions in insulators
• Classifying and measuring the geometry of the quantum ground state manifold
• Transition-metal dimers and physical limits on magnetic anisotropy
• Elementary Excitations of Ferromagnetic Metal Nanoparticles
• Chern-number spin Hamiltonians for magnetic nano-clusters by DFT methods
• Chern number spins of Mn acceptor magnets in GaAs
• Measuring Berry curvature with quantum Monte Carlo
• Mesoscopic bound on anisotropy in itinerant ferromagnets
• Coexistence of Van Hove Singularities and Pseudomagnetic Fields in Modulated Graphene Bilayer
• Landau-Zener quantum tunneling in disordered nanomagnets