arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 0709.2389cond-mat.mtrl-scicond-mat.mes-hall
收藏

二色性f和规则与晶体的轨道磁化强度

Dichroic f-sum rule and the orbital magnetization of crystals

Ivo Souza, David Vanderbilt

摘要:

在电偶极近似下,研究了时间反演对称性破缺晶体的磁圆二色性谱。利用Kubo-Greenwood公式计算反对称光学电导率的吸收部分,将其频率积分作为基态性质。我们表明,在绝缘体中,这个量与围绕其中心的被占据的Wannier轨道的循环成正比(更准确地说,与其规范不变部分成正比)。这不同于净循环,或基态轨道磁化,它有两个额外的贡献:(i)剩余的Wannier自转,和(ii)“巡回”循环产生的质心运动的Wannier轨道,无论是在表面上和内部的样品。贡献(i)和(ii)不是单独有意义的,因为它们各自的值取决于Wannier函数的特定选择。然而,它们的总和是规范不变的,并且可以从两个实验的组合中推断出来:在足够宽的范围内测量磁光谱以评估总和规则,以及对总轨道磁化的旋磁测定。

英文摘要:

We consider the magnetic circular dichroism spectrum of a crystal with broken time-reversal symmetry in the electric-dipole approximation. Using the Kubo-Greenwood formula for the absorptive part of the antisymmetric optical conductivity, its frequency integral is recast as a ground-state property. We show that in insulators this quantity is proportional to the circulation of the occupied Wannier orbitals around their centers (more precisely, to the gauge-invariant part thereof). This differs from the net circulation, or ground state orbital magnetization, which has two additional contributions: (i) the remaining Wannier self-rotation, and (ii) the ``itinerant'' circulation arising from the center-of-mass motion of the Wannier orbitals, both on the surface and in the interior of the sample. Contributions (i) and (ii) are not separately meaningful, since their individual values depend on the particular choice of Wannier functions. Their sum is however gauge-invariant, and can be inferred from a combination of two experiments: a measurement of the magneto-optical spectrum over a sufficiently wide range to evaluate the sum rule, and a gyromagnetic determination of the total orbital magnetization.

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。

↑