A5002523571- 2D Materials and Applications
- Strong Light-Matter Interactions
- Quantum and electron transport phenomena
- Mechanical and Optical Resonators
- MXene and MAX Phase Materials
- Perovskite Materials and Applications
- Nanowire Synthesis and Applications
- Semiconductor Quantum Structures and Devices
- Topological Materials and Phenomena
- Magnetic properties of thin films
- Iron-based superconductors research
- Electronic and Structural Properties of Oxides
- Physics of Superconductivity and Magnetism
- Plasmonic and Surface Plasmon Research
- Advancements in Semiconductor Devices and Circuit Design
- Heusler alloys: electronic and magnetic properties
- Graphene research and applications
- Molecular Junctions and Nanostructures
- Quantum Electrodynamics and Casimir Effect
- Thermal Radiation and Cooling Technologies
- ZnO doping and properties
- Boron and Carbon Nanomaterials Research
- Magnetic Field Sensors Techniques
- Atomic and Subatomic Physics Research
- Quantum-Dot Cellular Automata
Technical University of Munich
2025
Munich Center for Quantum Science and Technology
2025
TU Dresden
2023-2024
Complexity and Topology in Quantum Matter
2023-2024
Hochschule für Technik und Wirtschaft Dresden – University of Applied Sciences
2024
City College of New York
2021-2024
City University of New York
2022
Ioffe Institute
2022
National Research University Higher School of Economics
2022
Center for Discovery
2022
Correlated quantum phenomena in one-dimensional (1D) systems that exhibit competing electronic and magnetic order are of strong interest for the study fundamental interactions excitations, such as Tomonaga-Luttinger liquids topological orders defects with properties completely different from quasiparticles expected their higher-dimensional counterparts. However, clean 1D difficult to realize experimentally, particularly magnetically ordered systems. Here, we show van der Waals layered...
The layered, air-stable van der Waals antiferromagnetic compound CrSBr exhibits pronounced coupling among its optical, electronic, and magnetic properties. As an example, exciton dynamics can be significantly influenced by lattice vibrations through exciton-phonon coupling. Using low-temperature photoluminescence spectroscopy, we demonstrate the effective between excitons phonons in nanometer-thick CrSBr. By careful analysis, identify that satellite peaks predominantly arise from interaction...
Nanowires induce mechanical deformations in monolayer semiconductors, creating potential channels that guide optical excitations.
Abstract Many surprising properties of quantum materials result from Coulomb correlations defining electronic quasiparticles and their interaction chains. In van der Waals layered crystals, enhanced have been tailored in reduced dimensions, enabling excitons with giant binding energies emergent phases including ferroelectric, ferromagnetic multiferroic orders. Yet, correlation design has primarily relied on structural engineering. Here we present quantitative experiment–theory proof that...
Atomic-level defects in van der Waals (vdW) materials are essential building blocks for quantum technologies and sensing applications. The layered magnetic semiconductor CrSBr is an outstanding candidate exploring optically active owing to a direct gap addition rich phase diagram including recently hypothesized defect-induced order at low temperature. Here, we show that probes of the local environment. We observe spectrally narrow (1 meV) defect emission correlated with both bulk additional...
We explore the electronic structure of paramagnetic CrSBr by comparative first principles calculations and angle-resolved photoemission spectroscopy. theoretically approximate phase using a supercell hosting spin configurations with broken long-range order applying quasiparticle self-consistent $GW$ theory, without inclusion excitonic vertex corrections to screened Coulomb interaction (QS$GW$ QS$G\hat{W}$, respectively). Comparing quasi-particle band data collected at 200 K results in...
Among atomically thin semiconductors, CrSBr stands out as both its bulk and monolayer forms host tightly bound, quasi-one-dimensional excitons in a magnetic environment. Despite pivotal importance for solid-state research, the exciton lifetime has remained unknown. While terahertz polarization probing can directly trace all excitons, independently of interband selection rules, corresponding large far-field foci substantially exceed lateral sample dimensions. Here, we combine spectroscopy...
Layered magnetic materials are becoming a major platform for future spin-based applications. Particularly, the air-stable van der Waals compound CrSBr is attracting considerable interest due to its prominent magneto-transport and magneto-optical properties. In this work, we observe transition from antiferromagnetic ferromagnetic behavior in crystals exposed high-energy, non-magnetic ions. Already at moderate fluences, ion irradiation induces remanent magnetization with hysteresis adapting...
van der Waals heterostructures composed of two-dimensional (2D) transition metal dichalcogenides and vdW magnetic materials offer an intriguing platform to functionalize valley excitonic properties in nonmagnetic TMDs. Here, we report magneto photoluminescence (PL) investigations monolayer (ML) MoSe2 on the layered A-type antiferromagnetic (AFM) semiconductor CrSBr under different field orientations. Our results reveal a clear influence order optical MoSe2, such as anomalous...
Abstract The spin–orbit coupling (SOC) in semiconductors is strongly influenced by structural asymmetries, as prominently observed bulk crystal structures that lack inversion symmetry. Here we study an additional effect on the SOC: asymmetry induced large interface area between a nanowire core and its surrounding shell. Our experiments purely wurtzite GaAs/AlGaAs core/shell nanowires demonstrate optical spin injection into single free-standing determine effective electron g -factor of...
We present a detailed study on the static magnetic properties of individual permalloy nanotubes (NTs) with hexagonal cross-sections. Anisotropic magnetoresistance (AMR) measurements and scanning transmission X-ray microscopy (STXM) are used to investigate their ground states its stability. find that magnetization in zero applied field is very stable vortex state. Its origin attributed strong growth-induced anisotropy easy axis perpendicular long tubes. AMR NTs combination micromagnetic...
van der Waals magnetic materials are an ideal platform to study low-dimensional magnetism. Opposed other members of this family, the semiconductor CrSBr is highly resistant degradation in air, which, addition its exceptional optical, electronic, and properties, reason compound receiving considerable attention at moment. For many years, phase diagram seemed be well-understood. Recently, however, several groups observed a transition magnetometry measurements temperatures around 40 K that not...
We present a scanning magnetic force sensor based on an individual magnet-tipped GaAs nanowire (NW) grown by molecular beam epitaxy. Its tip consists of final segment single-crystal MnAs formed sequential crystallization the liquid Ga catalyst droplet. characterize mechanical and properties such NWs measuring their flexural response in applied field. Comparison with numerical simulations allows identification equilibrium magnetization configurations, which some cases include vortices. To...
We study theoretically effects of an anisotropic elastic strain on the exciton energy spectrum fine structure and optical selection rules in atom-thin crystals based transition-metal dichalcogenides. The presence breaks chiral at $\bm K$-points Brillouin zone makes transitions linearly polarized. orientation induced linear polarization is related to main axes tensor. Elastic provides additive contribution splitting agreement with experimental evidence obtained from uniaxially strained...
Views Icon Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Twitter Facebook Reddit LinkedIn Tools Reprints and Permissions Cite Search Site Citation Stephan Furthmeier, Florian Dirnberger, Joachim Hubmann, Benedikt Bauer, Tobias Korn, Christian Schüller, Josef Zweck, Elisabeth Reiger, Dominique Bougeard; Long exciton lifetimes in stacking-fault-free wurtzite GaAs nanowires. Appl. Phys. Lett. 1 December 2014; 105 (22): 222109....
Ultrathin CrSBr flakes are exfoliated in situ on Au(111) and Ag(111) their electronic structure is studied by angle-resolved photoemission spectroscopy. The thin flakes' properties drastically different from those of the bulk material also substrate dependent. For both substrates, a strong charge transfer to observed, partly populating conduction band giving rise highly anisotropic Fermi contour with an Ohmic contact substrate. fundamental gap strongly renormalized compared bulk. flake...
We investigate the incorporation of manganese into self-catalyzed GaAs nanowires grown in molecular beam epitaxy. Our study reveals that Mn accumulates liquid Ga droplet and no significant nanowire is observed. Using a sequential crystallization droplet, we then demonstrate deterministic epitaxial growth MnAs segments at tip. This technique may allow seamless integration multiple room-temperature ferromagnetic with high-crystalline quality.
Analytic and numerical studies on curved magnetic nano-objects predict numerous exciting effects that can be referred to as magneto-chiral effects, which do not originate from intrinsic Dzyaloshinskii-Moriya interaction or interface-induced anisotropies. In constrast, these chiral stem isotropic exchange dipole-dipole interaction, present in all materials, acquire asymmetric contributions case of geometry the specimen. As a result, for example, spin-wave dispersion round nanotubes becomes...
Fluorescent proteins (FPs) have recently emerged as a serious contender for realizing ultralow threshold room temperature exciton-polariton condensation and lasing. This contribution investigates the thermalization of FP microcavity exciton-polaritons upon optical pumping under ambient conditions. Polariton cooling is realized using new molecule, called mScarlet, coupled strongly to modes in Fabry-Pérot cavity. Interestingly, at excitation energy (fluence) ≈9 nJ per pulse (15.6 mJ cm
Transition metal dichalcogenides (TMDCs) have been in the limelight for past decade as a candidate several optoelectronic devices and versatile test bed various fundamental light–matter interaction phenomena thanks to their exceptional linear optical properties arising from large binding energy, strong spin–orbit coupling, valley physics monolayer (ML) limit. They also boast nonlinear fortified by excitonic responses these systems. However, second-order are mostly restricted ML limit, owing...
We theoretically investigate the D'yakonov-Perel' spin-relaxation properties in diffusive wurtzite semiconductor nanowires and their impact on quantum correction to conductivity. Although lifetime of long-lived spin states is limited by dominant $k$-linear spin-orbit contributions bulk, these terms show almost no effect finite-size nanowires. Here, essentially determined small $k$-cubic nearly independent wire radius. At same time, possess general a complex helical structure real space that...
We experimentally demonstrate ultralong spin lifetimes of electrons in the one-dimensional (1D) quantum limit semiconductor nanowires. Optical probing single wires different diameters reveals an increase relaxation time by orders magnitude as become increasingly confined until only a 1D sub-band is populated after thermalization. find observed more than 200 ns to result from robustness against major mechanisms, highlighting promising potential these for long-range transport coherent information.