Impurity-induced orbital magnetization in a Rashba electron gas

Abstract

We investigate the induced orbital magnetization density in a Rashba electron gas with magnetic impurities. Relying on classical electrodynamics, we obtain this quantity through the bound currents composed of a paramagnetic and a diamagnetic-like contribution which emerge from the spin-orbit interaction. Similar to Friedel charge ripples, the bound currents and the orbital magnetization density oscillate as function of distance away from the impurity with characteristic wavelengths defined by the Fermi energy and the strength of the Rashba spin-orbit interaction.The net induced orbital magnetization was found to be of the order of magnitude of its spin counterpart. Besides the exploration of the impact of the electronic filling of the impurity states, we investigate and analyze the orbital magnetization induced by an equilateral frustrated trimer in various non-collinear magnetic states. On the one hand, we confirm that non-vanishing threespin chiralities generate a finite orbital magnetization density. On the other hand, higher order contributions lead to multiple-spin chiralities affecting non-trivially and significantly the overall magnitude and sign of the orbital magnetization. arXiv:1806.02158v1 [cond-mat.mes-hall]

Numerical study of disorder on the orbital magnetization in two dimensions

“…This enhancement of orbital magnetic moment at intermediate disorder reflects the emergence of the metal state from another respect. Similarly, magnetic impurities was also found to induce remarkable OM in a Rashba electron gas [58]. After this peak at disorder W ∼ 10, all electronic motions go towards a final localization M, σ int…”

Spin, atomic, and interatomic orbital magnetism induced by 3d nanostructures deposited on transition metal surfaces

“…The dependence on the spin polarizability of the surface is investigated by comparing Rh with Pd and Ir with Pt, respectively, as Pd and Pt are known to have a very large spin polarizability [20][21][22][23][25][26][27] . In addition, Ag(111) and Au(111) host free-electron-like surface states (which are Rashba-split in the case of Au) 28,29 , and can therefore be compared to other works, which modelled ground-state currents induced in a Rashba electron gas due to the presence of magnetic impurities 30 . We also address how the surface magnetism depends on the size of the magnetic nanostructure, using a Co trimer on Pt(111) as example, and whether the induced magnetic moments can be detected and mapped through the magnetic stray fields that they generate.…”

Transverse Transport in Two-Dimensional Relativistic Systems with Non-Trivial Spin Textures

“…In the weak coupling regime [29,34], the (T )matrix is computed using the second Born approximation. Inside the skyrmion, the electron propagates under a spin-orbit field in a structure asymmetric environment [39,40]. This approach allows to establish a transparent relation between the scattering cross section and the orientation of the magnetic moments in the presence of relativistic effects (as shown in Supplementary Material [38]).…”

“…In order to illustrate and identify the contribution of the NHE to the Hall signal, we consider a magnetic trimer, which is the smallest nano-structure capable of generating a finite scalar spin chirality [40,42]. The three magnetic atoms form an equilateral triangle separated by a distance of d = 3 Å.…”