arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2007.06044cond-mat.str-el
收藏

量子线中自旋轨道耦合引起的各向异性近藤屏蔽

Anisotropic Kondo screening induced by spin-orbit coupling in quantum wires

E. Vernek, G. B. Martins, R. Zitko

摘要:

利用数值重整化群(NRG)方法研究了外磁场中磁杂质与具有Rashba和Dresselhaus自旋轨道耦合(SOC)的量子线的耦合.我们认为低填充制度的费米能量接近底部的带和报告的结果,在近藤制度的局部静态和动态特性。在没有场的情况下,尽管导带的SOC诱导的磁各向异性,但局部杂质性质在自旋空间中保持各向同性。在该领域的存在下,明确的指纹的各向异性揭示通过强场方向依赖的杂质自旋极化和光谱,特别是近藤峰高。详细的行为取决于杂质和能带$g$因子的相对大小。对于杂质$g$ -因子略低于能带$g$ -因子的情况下,最大的近藤峰抑制被发现为沿有效SOC场轴取向的场,而对于垂直于该方向的场,我们观察到补偿效应("近藤峰的复兴“):SOC抵消了局部塞曼场的近藤峰分裂效应。我们证明,SOC引起的各向异性,可测量的隧道光谱技术,可以帮助确定Rashba和Dresselhaus SOC强度的比率在电线。

英文摘要:

Using the numerical renormalization group (NRG) method we study a magnetic impurity coupled to a quantum wire with Rashba and Dresselhaus spin-orbit coupling (SOC) in an external magnetic field. We consider the low-filling regime with the Fermi energy close to the bottom of the band and report the results for local static and dynamic properties in the Kondo regime. In the absence of the field, local impurity properties remain isotropic in spin space despite the SOC-induced magnetic anisotropy of the conduction band. In the presence of the field, clear fingerprints of anisotropy are revealed through the strong field-direction dependence of the impurity spin polarization and spectra, in particular of the Kondo peak height. The detailed behavior depends on the relative magnitudes of the impurity and band $g$-factors. For the case of impurity $g$-factor somewhat lower than the band $g$-factor, the maximal Kondo peak suppression is found for field oriented along the effective SOC field axis, while for a field perpendicular to this direction we observe a compensation effect (``revival of the Kondo peak''): the SOC counteracts the Kondo peak splitting effects of the local Zeeman field. We demonstrate that the SOC-induced anisotropy, measurable by tunneling spectroscopy techniques, can help to determine the ratio of Rashba and Dresselhaus SOC strengths in the wire.

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。

↑