Spin-flip transitions and departure from the Rashba model in the Au(111) surface

Abstract

We present a detailed analysis of the spin-flip excitations induced by a periodic time-dependent electric field in the Rashba prototype Au(111) noble metal surface. Our calculations incorporate the full spinor structure of the spin-split surface states and employ a Wannier-based scheme for the spin-flip matrix elements. We find that the spin-flip excitations associated with the surface states exhibit an strong dependence on the electron momentum magnitude, a feature that is absent in the standard Rashba model [E. I. Rashba, Sov. Phys. Solid State 2, 1109 (1960)]. Furthermore, we demonstrate that the maximum of the calculated spin-flip absorption rate is about twice the model prediction. These results show that, although the Rashba model accurately describes the spectrum and spin polarization, it does not fully account for the dynamical properties of the surface states.

Microscopic origin of the relativistic splitting of surface states

“…In particular, Au(111) turns out to be not a paradigm case of an RB system, which explains the recently encountered "departure from the Rashba model" in the spin-flip excitations at Au(111). 59 Thus, neither the parabolicity of E(k ) nor the full in-plane spin polarization of the states are an indication of the RB scenario. The relativistic wave function modification revealed by Figs.…”

Infrared to terahertz optical conductivity ofn-type andp-type monolayerMoS2in the presence of Rashba spin-orbit coupling

“…As a consequence, spinŝ z is no longer a good quantum number [31][32][33] and it becomes possible to have transitions between spin-split electronic states. This enables the observation of spin-related optical phenomena that were found before to be presented in traditional 2D electron gasses (2DEGs) [25][26][27][28][29][30]. In ML-MoS 2 , there is a combination of both spin-coupling mechanisms with which one can expect to realize interesting spin-optics effects.…”

“…The control of carrier spin dynamics in semiconductor nanostructures is a key issue in spintronics and it can be achieved through the electrical manipulation of the SOC induced by the Rashba effect [22][23][24]. The investigation of optical properties such as collective excitations [25,26] and optical conductivities [27][28][29][30] has been conducted and show how the Rashba effect affects the optical properties of traditional 2D semiconductor based spintronic devices. This indicates that the Rashba effect has a strong influence on the plasmon modes and low-frequency optical spectrum.…”

Nondegenerate valleys in the half-metallic ferromagnet Fe/WS2

“…Above, f (E nk ) represents the Fermi-Dirac distribution function, while the integral is evaluated over the entire surface Brillouin zone. The transition matrix elements T α CV (k) are given by 37,50 T (α)…”

“…(2) are smooth in k space. Following this procedure 36,37 , we have, furthermore, been able to interpolate the T Figs. 4(c) and 4(d) is the high localization of the transition probability in hotspot regions around the K and K points, respectively.…”