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arXiv 2004.11735cond-mat.str-el
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单分子磁体中自旋-声子相互作用引起的隧道劈裂

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

K. Irländer, J. Schnack

摘要:

磁化的量子隧穿是使用单分子磁体(SMM)作为下一代存储设备的基本组成部分的主要障碍。在这种情况下,声子通常只被认为(微扰)作为扰动,促进自旋系统穿越各向异性势垒。在这里,我们证明了声子诱导隧道分裂的地面偶极子,然后减少所需的双稳态由于朗道-齐纳隧道的磁化的能力。有害的是那些修改自旋哈密顿量的声子,从而破坏了它关于场轴的旋转对称性。在我们的计算中,我们对待自旋和声子在同一个基础上进行量子计算的哈密顿量的单各向异性张量耦合到谐振子。

英文摘要:

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.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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