Spin tunnelling in mesoscopic systems

Pramana

Anupam Garg¹ 

[1] Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208, USA$$

关键词: Spin tunnelling;    spin path integrals;    discrete phase integral method;    diabolical points.;   

DOI  :  

学科分类：物理（综合）

来源: Indian Academy of Sciences

【 摘 要 】

We study spin tunnelling in molecular magnets as an instance of a mesoscopic phenomenon, with special emphasis on the molecule Fe8. We show that the tunnel splitting between various pairs of Zeeman levels in this molecule oscillates as a function of applied magnetic field, vanishing completely at special points in the space of magnetic fields, known as diabolical points. This phenomena is explained in terms of two approaches, one based on spin-coherent-state path integrals, and the other on a generalization of the phase integral (or WKB) method to difference equations. Explicit formulas for the diabolical points are obtained for a model Hamiltonian.

【 授权许可】

Unknown