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Oscillation of the tunnel splitting in nanospin systems within the particle mapping formalism

Sahng-Kyoon Yoo·Soo-Young Lee·Dal-Ho Yoon·Chang-Soo Park
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Abstract

The oscillation of tunnel splitting in the biaxial spin system within magnetic field along the anisotropy axis is analyzed within the particle mapping approach, rather than in the (θ-ϕ) spin coherent-state representation. In our mapping procedure, the spin system is transformed into a particle moving in the restricted $S^1$ geometry whose wave function subjects to the boundary condition involving additional phase shift. We obtain the new topological phase that plays the same role as the Wess-Zumino action in spin coherent-state representation. Considering the interference of two possible trajectories, instanton and anti-instanton, we get the identical condition for the field at which tunneling is quenched, with the previous result within spin coherent-state representation.

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Sahng-Kyoon Yoo, Soo-Young Lee, Dal-Ho Yoon, Chang-Soo Park. 1999-09-20. Oscillation of the tunnel splitting in nanospin systems within the particle mapping formalism. https://doi.org/10.1103/physrevb.62.3014

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