Spin Wave Effects in Transport between a Ferromagnet and a Weyl Semimetal Surface

JETP Letters - We experimentally investigate spin-polarized transport between a ferromagnetic Ni electrode and a surface of Weyl semimetal, realized in a thick WTe2 single crystal. For highly...     

Electronic and vibrational spectra of a gel of single-wall carbon nanotubes in an ionic liquid

A gel of single-wall carbon nanotubes in an ionic liquid has been prepared using the technique of mixing nanotubes with ionic liquids. The gel obtained has a high concentration of nanotubes (～1%). The absorption spectra of the gel and its individual components have been measured. The absorption spectrum of the gel exhibits reconstruction of the electronic and vibrational spectra of the gel with respect to its individual components. This reconstruction is explained by the interaction of nanotubes with the ionic liquid in the gel structure. Reconstruction of the electronic subsystem of nanotubes has also been observed in a suspension of nanotubes in an aqueous solution of a surfactant.     

Coalescence of Andreev Bound States on the Surface of a Chiral Topological Semimetal

JETP Letters - We experimentally investigate the magnetic field dependence of Andreev transport through a region of proximity-induced superconductivity in the CoSi topological chiral semimetal....     

Cyanoethylation of substituted 4-azafluorenes. Synthesis of spiro-[4-azafluorene-9-cyclopentenes]

Cyanoethylation of 9-phenacyl(β-hydroxy-β-phenylethyl-, or acetamido)-4-azafluorenes under conditions of the Michael reaction occurs regioselectively at position 9. 1-Amino-4-azafluorene under these conditions forms 1-[N,N-di-(β-cyanoethyl)amino)]-(9-β-cyanoethyl)-4-azafluorene. The cyclization of 9-(β-cyanoethyl)-9-phenacyl-4-azafluorene has been carried out into 1′-cyano-2′-phenylspiro[4-aza-fluorene-9,4′-cyclopentene and 1′-imino-2′-hydroxybenzylidenespiro[4-azafluorene-9.3′-cyclopentane]-substituted in the five-membered fragment. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1496–1501, October, 2006.     

Evidence of the Ferroelectric Polarization in Charge Transport through WTe2 Weyl Semimetal Surface

JETP Letters - We investigate electron transport along the surface of WTe2 three-dimensional single crystals, which are characterized by the coexistence of the conductivity and ferroelectricity of...     

Green Deep Eutectic Solvents for Microwave-Assisted Biomass Delignification and Valorisation

Aiming to fulfil the sustainability criteria of future biorefineries, a novel biomass pretreatment combining natural deep eutectic solvents (NaDESs) and microwave (MW) technology was developed. Results showed that NaDESs have a high potential as green solvents for lignin fractionation/recovery and sugar release in the following enzymatic hydrolysis. A new class of lignin derived NaDESs (LigDESs) was also investigated, showing promising effects in wheat straw delignification. MW irradiation enabled a fast pretreatment under mild condition (120 °C, 30 min). To better understand the interaction of MW with these green solvents, the dielectric properties of NaDESs were investigated. Furthermore, a NaDES using the lignin recovered from biomass pretreatment as hydrogen bond donor was prepared, thus paving the way for a “closed-loop” biorefinery process.     

Liouville classification of integrable geodesic flows on a torus of revolution in a potential field

A Liouville classification of integrable Hamiltonian systems being geodesic flows on a twodimensional torus of revolution in an invariant potential field is obtained in the case of linear integral. This classification is obtained using the Fomenko–Zieschang invariant (so called marked molecules) of the systems under consideration. All types of bifurcation curves are described. A classification of singularities of the system solutions is also obtained.     

Realization of a Double-Slit SQUID Geometry by Fermi Arc Surface States in a WTe<Subscript>2</Subscript> Weyl Semimetal

We experimentally study electron transport between two superconducting indium leads, coupled to the WTe₂ crystal surface. WTe₂ is characterized by presence of Fermi arc surface states, as a predicted type-II Weyl semimetal candidate. We demonstrate Josephson current in unprecedentedly long 5 µm In–WTe₂–In junctions, which is confirmed by I–V curves evolution with temperature and magnetic field. The Josephson current is mostly carried by the topological surface states, which we demonstrate in a double-slit superconducting quantum interference device geometry, realized by coupling the opposite WTe₂ crystal surfaces.