Phonon-assisted tunneling in the quantum regime of Mn12 acetate

被引：63

作者：

Chiorescu, I

Giraud, R

Jansen, AGM

Caneschi, A

Barbara, B

机构：

[1] CNRS, Lab Magnetisme Louis Neel, F-38042 Grenoble 09, France

[2] CNRS, MPI, GHMFL, Lab Champs Magnet Intenses, F-38042 Grenoble, France

[3] Univ Florence, Dept Chem, I-50144 Florence, Italy

来源：

PHYSICAL REVIEW LETTERS | 2000年 / 85卷 / 22期

关键词：

D O I：

10.1103/PhysRevLett.85.4807

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

Longitudinal or transverse magnetic fields applied on a crystal of Mn-12 acetate allows one to observe independent tunnel transitions between m = -S + p and m = S - n - p (n = 6-10, p = 0-2 in longitudinal field and n = p = 0 in transverse field). We observe a smooth transition tin longitudinal) from coherent ground-state to thermally activated tunneling. Furthermore, two ground;state relaxation regimes show a crossover between quantum spin relaxation far from equilibrium and near equilibrium, when the environment destroys multimolecule correlations. Finally, we stress that the complete Hamiltonian of Mn-12 should contain odd spin operators of low order.

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页码：4807 / 4810

页数：4

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