Complexation of 1,3-dihetaryl-5-phenyl-2-pyrazoline Derivatives with Polyvalent Metal Ions: Quantum Chemical Modeling and Experimental Investigation

1,3,5-Triaryl-2-pyrazoline derivatives with a pyridine ring in position 1 and 2-benzimidazolyl or 2-benzothiazolyl bicycles in position 3 were synthesized. Spectral properties in solvents of similar polarity, i.e. aprotic acetonitrile and in protic methanol, were studied, complexation with cadmium and mercury ions in acetonitrile was elucidated as well. Quantum-chemical modeling with application of the elements of Bader's atoms-in-molecules (AIM) theory of the title molecules conformational structure and 1:1 stoichiometry complexes formed with polyvalent metals of various nature (Mg, Zn, Cd, Pb, Hg, Ba) was conducted. The principal possibility of “nitrogen-sulfur” switching of the metal ions binding sites for the benzothiazole derivative was revealed, and makes possible to classify this compound as “smart ligand”

Adiabatic Control of Spin-Wave Propagation using Magnetisation Gradients

Spin waves are of large interest as data carriers for future logic devices. However, due to the strong anisotropic dispersion relation of dipolar spin-waves in in-plane magnetised films the realisation of two-dimensional information transport remains a challenge. Bending of the energy flow is prohibited since energy and momentum of spin waves cannot be conserved while changing the direction of wave propagation. Thus, non-linear or non-stationary mechanisms are usually employed. Here, we propose to use reconfigurable laser-induced magnetisation gradients to break the system's translational symmetry. The resulting changes in the magnetisation shift the dispersion relations locally and allow for operating with different spin-wave modes at the same frequency. Spin-wave momentum is first transformed via refraction at the edge of the magnetisation gradient region and then adiabatically modified inside it. Along these lines the spin-wave propagation direction can be controlled in a broad frequency range with high efficiency

Perspective on Nanoscaled Magnonic Networks

With the rapid development of artificial intelligence in recent years, mankind is facing an unprecedented demand for data processing. Today, almost all data processing is performed using electrons in conventional complementary metal-oxide-semiconductor (CMOS) circuits. Over the past few decades, scientists have been searching for faster and more efficient ways to process data. Now, magnons, the quanta of spin waves, show the potential for higher efficiency and lower energy consumption in solving some specific problems. While magnonics remains predominantly in the realm of academia, significant efforts are being made to explore the scientific and technological challenges of the field. Numerous proof-of-concept prototypes have already been successfully developed and tested in laboratories. In this article, we review the developed magnonic devices and discuss the current challenges in realizing magnonic circuits based on these building blocks. We look at the application of spin waves in neuromorphic networks, stochastic and reservoir computing and discuss the advantages over conventional electronics in these areas. We then introduce a new powerful tool, inverse design magnonics, which has the potential to revolutionize the field by enabling the precise design and optimization of magnonic devices in a short time. Finally, we provide a theoretical prediction of energy consumption and propose benchmarks for universal magnonic circuits.Comment: 9 pages, 1 figur

Nanoscaled magnon transistor based on stimulated three-magnon splitting

Magnonics is a rapidly growing field, attracting much attention for its potential applications in data transport and processing. Many individual magnonic devices have been proposed and realized in laboratories. However, an integrated magnonic circuit with several separate magnonic elements has yet not been reported due to the lack of a magnonic amplifier to compensate for transport and processing losses. The magnon transistor reported in [Nat. Commun. 5, 4700, (2014)] could only achieve a gain of 1.8, which is insufficient in many practical cases. Here, we use the stimulated three-magnon splitting phenomenon to numerically propose a concept of magnon transistor in which the energy of the gate magnons at 14.6 GHz is directly pumped into the energy of the source magnons at 4.2 GHz, thus achieving the gain of 9. The structure is based on the 100 nm wide YIG nano-waveguides, a directional coupler is used to mix the source and gate magnons, and a dual-band magnonic crystal is used to filter out the gate and idler magnons at 10.4 GHz frequency. The magnon transistor preserves the phase of the signal and the design allows integration into a magnon circuit.Comment: 8 pages, 3 figure