31 research outputs found
All-optical flip-flops using electrically pumped microdisk lasers integrated on silicon
We demonstrate flip-flop operation using the directional bistability in ultra-small microdisks (7.5 mu m diameter) heterogeneously bonded on a silicon chip. The pulse energies are only 1.8 fJ and the bias current is 3.5 mA
Transmission of pillar-based photonic crystal waveguides in InP technology
Waveguides based on line defects in pillar photonic crystals have been fabricated in InP/InGaAsP/InP technology. Transmission measurements of different line defects are reported. The results can be explained by comparison with two-dimensional band diagram simulations. The losses increase substantially at mode crossings and in the slow light regime. The agreement with the band diagrams implies a good control on the dimensions of the fabricated features, which is an important step in the actual application of these devices in photonic integrated circuit
Extraction of Dzyaloshinksii-Moriya interaction from propagating spin waves validated
The interfacial Dzyaloshinksii-Moriya interaction (iDMI) is of great interest
in thin-film magnetism because of its ability to stabilize chiral spin
textures. It can be quantified by investigating the frequency non-reciprocity
of oppositely propagating spin waves. However, as the iDMI is an interface
interaction the relative effect reduces when the films become thicker making
quantification more difficult. Here, we utilize all-electrical Propagating Spin
Wave Spectroscopy (PSWS) to disentangle multiple contributions to spin wave
frequency non-reciprocity to determine the iDMI. This is done by investigating
non-reciprocities across a wide range of magnetic layer thicknesses (from 4 to
26 nm) in Pt/Co/Ir, Pt/Co/Pt, and Ir/Co/Pt stacks. We find the expected sign
change in the iDMI when inverting the stack order, and a negligible iDMI for
the symmetric Pt/Co/Pt. We additionally extract a difference in surface
anisotropies and find a large contribution due to the formation of different
crystalline phases of the Co, which is corroborated using nuclear magnetic
resonance and high-resolution transmission-electron-microscopy measurements.
These insights will open up new avenues to investigate, quantify and
disentangle the fundamental mechanisms governing the iDMI, and pave a way
towards engineered large spin-wave non-reciprocities for magnonic applications.Comment: 12 pages, 2 figure