| 1. |
|
|
| 2. |
- Usachov, D. Yu, et al.
(författare)
-
Cubic Rashba Effect in the Surface Spin Structure of Rare-Earth Ternary Materials
- 2020
-
Ingår i: Physical Review Letters. - 0031-9007. ; 124:23
-
Tidskriftsartikel (refereegranskat)abstract
- Spin-orbit interaction and structure inversion asymmetry in combination with magnetic ordering is a promising route to novel materials with highly mobile spin-polarized carriers at the surface. Spin-resolved measurements of the photoemission current from the Si-terminated surface of the antiferromagnet TbRh2Si2 and their analysis within an ab initio one-step theory unveil an unusual triple winding of the electron spin along the fourfold-symmetric constant energy contours of the surface states. A two-band k·p model is presented that yields the triple winding as a cubic Rashba effect. The curious in-plane spin-momentum locking is remarkably robust and remains intact across a paramagnetic-antiferromagnetic transition in spite of spin-orbit interaction on Rh atoms being considerably weaker than the out-of-plane exchange field due to the Tb 4f moments.
|
|
| 3. |
- Jmerik, V. N., et al.
(författare)
-
Site-Controlled Growth of GaN Nanorods with Inserted InGaN Quantum Wells on mu-Cone Patterned Sapphire Substrates by Plasma-Assisted MBE
- 2018
-
Ingår i: Semiconductors (Woodbury, N.Y.). - : MAIK NAUKA/INTERPERIODICA/SPRINGER. - 1063-7826 .- 1090-6479. ; 52:5, s. 667-670
-
Tidskriftsartikel (refereegranskat)abstract
- We report on a new approach to fabricate regular arrays of GaN nanorods (NRs) with InGaN QWs by plasma-assisted molecular-beam epitaxy (PA MBE) on micro-cone patterned sapphire substrates (mu-CPSSs). A two-stage PA MBE fabrication process of GaN NRs has been developed, starting with a high temperature nucleation layer growth at metal-rich conditions to aggregate selectively GaN nucleus on c-oriented areas of the mu-CPSSs and followed by growth of 1-mu m-thick GaN NRs at strongly nitrogen-rich conditions exactly on the cone tips. These results are explained by energetically favorable GaN growth on the (000 (1) over bar) oriented sapphire surface. Both micro-photoluminescence and micro-cathodoluminescence confirm the formation of regular array of optically and spectrally isolated NRs without usage of any nanolithography.
|
|
| 4. |
- Generalov, A., et al.
(författare)
-
Strong spin-orbit coupling in the noncentrosymmetric Kondo lattice
- 2018
-
Ingår i: Physical Review B. - 2469-9950. ; 98:11
-
Tidskriftsartikel (refereegranskat)abstract
- Strong spin-orbit coupling (SOC) in combination with a lack of inversion symmetry and exchange magnetic interaction proves to be a sophisticated instrument allowing efficient control of the spin orientation, energy and trajectories of two-dimensional (2D) electrons and holes trapped at surfaces or interfaces. Exploiting Kondo-related phenomena and crystal-electric-field effects at reduced dimensionalities opens new opportunities to handle their spin-dependent properties offering novel functionalities. We consider here a 2D Kondo lattice represented by a Si-Ir-Si-Yb (SISY) surface block of the heavy-fermion material YbIr2Si2. We show that the Kondo interaction with 4f moments allows finely tuning the group velocities of the strongly spin-polarized carriers in 2D itinerant states of this noncentrosymmetric system. To unveil the peculiarities of this interaction, we used angle-resolved photoemission measurements complemented by first-principles calculations. We established that the strong SOC of the Ir atoms induces spin polarization of the 2D states in SISY block, while the 2D lattice of Yb 4f moments acts as a source for coherent f-d interplay. The strong SOC and lack of inversion symmetry turn out to lead not only to the anticipated Rashba-like splitting of the 2D states, but also to spin splitting of the 4f Kramers doublets. They couple temperature-dependently to the spin-polarized 2D states and thereby guide the properties of the latter.
|
|
