Detection of femtosecond spin injection into a thin gold layer by time and spin resolved photoemission

Abstract

The ultrafast demagnetization effect allows for the generation of femtosecond spin current pulses, which is expected to extend the fields of spin transport and spintronics to the femtosecond time domain. thus far, directly observing the spin polarization induced by spin injection on the femtosecond time scale has not been possible. Herein, we present time-and spin-resolved photoemission results of spin injection from a laser-excited ferromagnet into a thin gold layer. The injected spin polarization is aligned along the magnetization direction of the underlying ferromagnet. Its decay time depends on the thickness of the gold layer, indicating that transport as well as storage of spins are relevant. this capacitive aspect of spin transport may limit the speed of future spintronic devices.

Ultrafast photoinduced dynamics in Prussian blue analogues

“…New experimental approaches, with fs temporal resolution, are also being pursued in this field, such as XFELs, [56][57][58][59][60] X-ray magnetic circular dichroism (XMCD), 61,62 and spin-resolved photoemission. 63,64 Somewhere in between the detailed understanding at the molecular level and the complex multi-dimensional interactions in a magnetic solid, lies molecule-based materials. These are made from molecular building blocks and, by using the right linker, it is possible to form long-range magnetic order.…”

Substrate mediated properties of gold monolayers on SiC

“…Furthermore, the fact that thin gold layers are of importance to the field of spin transport 53 implies that a winning combination of atomically thin gold and graphene may also boost the development of novel-type applications beyond the already proposed graphene-based spintronic devices. 54,55…”

Control of light–valley interactions in 2D transition metal dichalcogenides with nanophotonic structures

“…8). 31,106,[115][116][117][118][119] As we have discussed, the introduction of nanophotonic structures can either modulate the decay rate of valley excitons by their nearfield or alleviate the effect from intervalley scattering through the strong coupling interaction, which results in a modified exciton radiative lifetime and valley lifetime. Additionally, the plasmon decay and the subsequent processes of hot carrier generation and injection appear at an ultrashort timescale (<1 ps), which is comparable to the valley lifetime of monolayer TMDCs.…”

“…In addition, it is possible to maintain the spin of carriers during the hot carrier injection process because of the long electron spin relaxation time (∼ps) in metal. [117][118][119] Despite the remarkable advances achieved, research in this emerging field is still in its infancy and more efforts are needed to achieve a full understanding of the mechanisms and realize robust manipulation of the valley pseudospin in TMDCs. First, the existing nanophotonic techniques can be improved to obtain a better control of the valley polarization.…”