A5057121154- Magnetic properties of thin films
- Physics of Superconductivity and Magnetism
- Perovskite Materials and Applications
- ZnO doping and properties
- Solid-state spectroscopy and crystallography
- Magneto-Optical Properties and Applications
- Magnetic and transport properties of perovskites and related materials
- 2D Materials and Applications
- Chalcogenide Semiconductor Thin Films
- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Shape Memory Alloy Transformations
- Iron-based superconductors research
- Optical and Acousto-Optic Technologies
- Photoreceptor and optogenetics research
- Metal and Thin Film Mechanics
- Strong Light-Matter Interactions
- Phase-change materials and chalcogenides
- Semiconductor Quantum Structures and Devices
- Quantum and electron transport phenomena
- Crystal Structures and Properties
- Luminescence and Fluorescent Materials
- Advanced Condensed Matter Physics
- Multiferroics and related materials
Heidelberg University
2022-2025
Schott (Germany)
2021-2024
Technical University of Munich
2021-2024
Johannes Gutenberg University Mainz
2017-2023
Abstract Using antiferromagnets as active elements in spintronics requires the ability to manipulate and read-out Néel vector orientation. Here we demonstrate for Mn 2 Au, a good conductor with high ordering temperature suitable applications, reproducible switching using current pulse generated bulk spin-orbit torques by magnetoresistance measurements. Reversible consistent changes of longitudinal resistance planar Hall voltage star-patterned epitaxial Au(001) thin films were densities ≃10 7...
Hybrid perovskite semiconductor materials are predicted to lock chirality into place and encode asymmetry their electronic states, while softness of crystal lattice accommodates strain maintain high quality with low defect densities, necessary for luminescence yields. We report photoluminescence quantum efficiencies as 39% degrees circularly polarized up 52%, at room temperature, in the chiral layered hybrid lead-halide perovskites (R/S/Rac)-3BrMBA 2 PbI 4 [3BrMBA =...
In the field of antiferromagnetic (AFM) spintronics, information about N\'eel vector, AFM domain sizes, and spin-flop fields is a prerequisite for device applications but not available easily. We have investigated domains spin-flop-induced changes patterns in ${\mathrm{Mn}}_{2}\mathrm{Au}$(001) epitaxial thin films by x-ray magnetic linear dichroism photoemission electron microscopy (PEEM) using up to 70 T. As-prepared ${\mathrm{Mn}}_{2}\mathrm{Au}$ exhibit with an average size...
Hybrid organic-inorganic networks that incorporate chiral molecules have attracted great attention due to their potential in semiconductor lighting applications and optical communication. Here, we introduce a organic molecule (R)/(S)-1-cyclohexylethylamine (CHEA) into bismuth-based lead-free structures with an edge-sharing octahedral motif, synthesize (R)/(S)-CHEA4Bi2BrxI10-x crystals thin films. Using single-crystal X-ray diffraction measurements density functional theory calculations,...
Antiferromagnets have large potential for ultrafast coherent switching of magnetic order with minimum heat dissipation. In materials such as Mn2Au and CuMnAs, electric rather than fields may control antiferromagnetic by Néel spin-orbit torques (NSOTs). However, these not yet been observed on time scales. Here, we excite thin films phase-locked single-cycle terahertz electromagnetic pulses monitor the spin response femtosecond magneto-optic probes. We observe signals whose symmetry, dynamics,...
In antiferromagnetic spintronics, it is essential to separate the resistance modifications of purely magnetic origin from other effects generated by current pulses intended switch N\'eel vector. We investigate magnetoresistance resulting field induced reorientations staggered magnetization epitaxial Mn2Au(001) thin films. The samples were exposed 60 T along different crystallographic in-plane directions Mn2Au(001), while their was measured. For aligned via a spin-flop transition parallel...
We observe the excitation of collective modes in THz range driven by recently discovered N\'{e}el spin-orbit torques (NSOT) metallic antiferromagnet Mn$_{2}$Au. Temperature dependent spectroscopy reveals a strong absorption mode centered near 1 THz, which upon heating from 4 K to 450 softens and looses intensity. Comparison with estimated eigenmode frequencies implies that observed is an in-plane antiferromagnetic resonance (AFMR) mode. The AFMR strength exceeds those found insulators,...
Spin–orbit coupling in the electronic states of solution-processed hybrid metal halide perovskites forms complex spin-textures band structures and allows for optical manipulation excited state spin-polarizations. Here, we report that motional narrowing acts on photoexcited spin-polarization CH3NH3PbBr3 thin films, which are doped at percentage-level with Mn2+ ions. Using ultrafast circularly polarized broadband transient absorption spectroscopy cryogenic temperatures, investigate spin...
Chiral hybrid metal-halide perovskites show low-symmetry crystal structures, large Rashba splitting, spin-filtering, and strong chiroptical activity. Circular dichroism circularly polarized photoluminescence have been investigated in chiral with increasingly distorted structures. Here, we report the fabrication of (R/S)-EBAPbI3 (EBA = α-ethylbenzylamine) single crystals, which possess highly octahedral structures a high angle variance value ∼68 degree2. Using control conditions, transfer...
Metallic antiferromagnets with broken inversion symmetry on the two sublattices, strong spin-orbit coupling and high N\'{e}el temperatures offer new opportunities for applications in spintronics. Especially Mn$_{2}$Au, temperature conductivity, is particularly interesting real-world applications. Here, manipulation of orientation staggered magnetization,\textit{\ i.e.} vector, by current pulses has been recently demonstrated, read-out limited to studies anisotropic magnetoresistance or X-ray...
The absence of stray fields, their insensitivity to external magnetic and ultrafast dynamics make antiferromagnets promising candidates for active elements in spintronic devices. Here, we demonstrate manipulation the Néel vector metallic collinear antiferromagnet Mn2Au by combining strain femtosecond laser excitation. Applying tensile along either two in-plane easy axes locally exciting sample a train pulses, align direction controlled applied strain. dependence on fluence suggests alignment...
Antiferromagnets are promising materials for future opto-spintronic applications since they show spin dynamics in the THz range and no net magnetization. Recently, layered van der Waals (vdW) antiferromagnets have been reported, which combine low-dimensional excitonic properties with complex spin-structure. While various methods fabrication of vdW 2D crystals exist, formation large area continuous thin films is challenging because either limited scalability, synthetic complexity, or low...
In this work we have investigated the exciton reflectance spectra of a high quality heterostructure with GaAs/AlGaAs quantum well in transverse magnetic field (Voigt geometry). It has been shown that application leads to decrease energy distance between spectral features related excitonlike polariton modes. This effect treated as magneto-induced increase mass. We hydrogenlike and diamagnetic models are insufficient describe behavior intermediate fields studied. Considering symmetry problem,...
Antiferromagnets have large potential for ultrafast coherent switching of magnetic order with minimum heat dissipation. In novel materials such as Mn$_2$Au and CuMnAs, electric rather than fields may control antiferromagnetic by N\'eel spin-orbit torques (NSOTs), which have, however, not been observed on time scales yet. Here, we excite thin films phase-locked single-cycle terahertz electromagnetic pulses monitor the spin response femtosecond magneto-optic probes. We observe signals whose...
Using optical orientation to manipulate magnetic moments in matter with light is a key objective opto-spintronics, however, realizations of such control on ultrafast timescales are limited. Here, we report moment magnetically doped metal halide perovskites. Employing intense pulses circularly polarized light, inject populations spin-polarized charge carriers pristine and manganese-doped MAPbBr3 thin films. transient Faraday rotation spectroscopy, probe the dynamics following photoexcitation...
The absence of stray fields, their insensitivity to external magnetic and ultrafast dynamics make antiferromagnets promising candidates for active elements in spintronic devices. Here, we demonstrate manipulation the N\'{e}el vector metallic collinear antiferromagnet Mn$_2$Au by combining strain femtosecond laser excitation. Applying tensile along either two in-plane easy axes locally exciting sample a train pulses, align direction controlled applied strain. dependence on fluence suggests...
Antiferromagnets are promising materials for future opto-spintronic applications since they show spin dynamics in the THz range and no net magnetization. Recently, layered van der Waals (vdW) antiferromagnets have been reported, which combine low-dimensional excitonic properties with complex spin-structure. While various methods fabrication of vdW 2D crystals exist, formation large area continuous thin films is challenging because either limited scalability, synthetic complexity, or low...
Bright circularly polarized photoluminescence in chiral layered hybrid lead-halide perovskitesShangpu Liu a, Yang Li b, Ulrich W. Paetzold Stanislav Bodnar Jonathan Zerhoch Andrii Shcherbakov Felix Deschler aa Physikalisch-Chemisches Institut, Universität Heidelbergb Institute of Microstructure Technology; Light Technology Institute, Karlsruhe TechnologyMaterials for Sustainable Development Conference (MATSUS)Proceedings MATSUS Spring 2024 (MATSUS24)#Chiral24 - Chiral Nanomaterials:...
Abstract The absence of stray fields, their insensitivity to external magnetic and ultrafast dynamics make antiferromagnets promising candidates for active elements in spintronic devices. Here, we demonstrate manipulation the Néel vector metallic collinear antiferromagnet Mn 2 Au by combining strain femtosecond laser excitation. Applying tensile along either two in-plane easy axes locally exciting sample a train pulses, align direction controlled applied strain. dependence on fluence...
In this work, we unveil the nanoscale inhomogeneities in films of some Methylammonium Lead Trihalide Perovskites with super-resolution nearfield optical microscopy and how they influence performance hybrid perovskites.