Charge Transfer and Asymmetric Coupling of MoSe Valleys to the Magnetic Order of CrSBr.

van der Waals heterostructures composed of two-dimensional (2D) transition metal dichalcogenides and vdW magnetic materials offer an intriguing platform to functionalize valley and excitonic properties in nonmagnetic TMDs. Here, we report magneto photoluminescence (PL) investigations of monolayer (ML) MoSe on the layered A-type antiferromagnetic (AFM) semiconductor CrSBr under different magnetic field orientations. Our results reveal a clear influence of the CrSBr magnetic order on the optical properties of MoSe, such as an anomalous linear-polarization dependence, changes of the exciton/trion energies, a magnetic-field dependence of the PL intensities, and a valley -factor with signatures of an asymmetric magnetic proximity interaction.

Pyrazinamide photodegradation on NiWO-palygorskite nanocomposites under polychromatic irradiation.

In this work, antibiotic pyrazinamide (PZA) photodegradation on palygorskite (Pal), NiWO crystals, and NiWO-Pal (2, 6, and 10%) nanocomposites was evaluated under polychromatic irradiation. In the characterization of the samples, XRD patterns displayed good crystallinity for NiWO crystals and nanocomposites. In addition, the diffractograms were used in the Rietveld refinement for phase indexing, revealing a wolframite-type monoclinic structure with the space group P2/c.

Unconventional Magnetization Generated from Electron Beam and Femtosecond Irradiation on α-AgWO: A Quantum Chemical Investigation.

Novel magnetic metals and metal oxides that use both the spin and charge of an electron offer exciting technological applications. Their discovery could boost research on functional nanoscale materials. Here, for the first time, we report the magnetization of α-AgWO under electron beam and femtosecond laser irradiation.

Deterministic Switching of the Growth Direction of Self-Catalyzed GaAs Nanowires.

The typical vapor-liquid-solid growth of nanowires is restricted to a vertical one-dimensional geometry, while there is a broad interest for more complex structures in the context of electronics and photonics applications. Controllable switching of the nanowire growth direction opens up new horizons in the bottom-up engineering of self-assembled nanostructures, for example, to fabricate interconnected nanowires used for quantum transport measurements. In this work, we demonstrate a robust and highly controllable method for deterministic switching of the growth direction of self-catalyzed GaAs nanowires.

Spin injection in n-type resonant tunneling diodes.

We have studied the polarized resolved photoluminescence of n-type GaAs/AlAs/GaAlAs resonant tunneling diodes under magnetic field parallel to the tunnel current. Under resonant tunneling conditions, we have observed two emission lines attributed to neutral (X) and negatively charged excitons (X-). We have observed a voltage-controlled circular polarization degree from the quantum well emission for both lines, with values up to -88% at 15 T at low voltages which are ascribed to an efficient spin injection from the 2D gases formed at the accumulation layers.

Spin effects in InAs self-assembled quantum dots.

We have studied the polarized resolved photoluminescence in an n-type resonant tunneling diode (RTD) of GaAs/AlGaAs which incorporates a layer of InAs self-assembled quantum dots (QDs) in the center of a GaAs quantum well (QW). We have observed that the QD circular polarization degree depends on applied voltage and light intensity. Our results are explained in terms of the tunneling of minority carriers into the QW, carrier capture by InAs QDs and bias-controlled density of holes in the QW.

Circular polarization in a non-magnetic resonant tunneling device.

We have investigated the polarization-resolved photoluminescence (PL) in an asymmetric n-type GaAs/AlAs/GaAlAs resonant tunneling diode under magnetic field parallel to the tunnel current. The quantum well (QW) PL presents strong circular polarization (values up to -70% at 19 T). The optical emission from GaAs contact layers shows evidence of highly spin-polarized two-dimensional electron and hole gases which affects the spin polarization of carriers in the QW.