A5023115837- Topological Materials and Phenomena
- Graphene research and applications
- 2D Materials and Applications
- Advanced Condensed Matter Physics
- Quantum and electron transport phenomena
- Physics of Superconductivity and Magnetism
- Magnetic properties of thin films
- Magnetic and transport properties of perovskites and related materials
- Electronic and Structural Properties of Oxides
- Advanced Thermoelectric Materials and Devices
- Rare-earth and actinide compounds
- Phase-change materials and chalcogenides
- Diamond and Carbon-based Materials Research
- Iron-based superconductors research
- Surface Chemistry and Catalysis
- High-pressure geophysics and materials
- Magnetism in coordination complexes
- Magnetic Field Sensors Techniques
- Advanced Semiconductor Detectors and Materials
- Surface and Thin Film Phenomena
- Photorefractive and Nonlinear Optics
- Advancements in Battery Materials
- Organic and Molecular Conductors Research
- Quantum many-body systems
- Theoretical and Computational Physics
Instituto de Nanociencia y Materiales de Aragón
2024-2025
Material Physics Center
2017-2024
Donostia International Physics Center
2013-2024
Ikerbasque
2018-2024
Universidad de Zaragoza
2024
University of the Basque Country
2021
St Petersburg University
2015-2019
National Research Tomsk State University
2010-2018
Max Planck Institute of Microstructure Physics
2011-2014
Using density functional theory and Monte Carlo calculations, we study the thickness dependence of magnetic electronic properties a van der Waals interlayer antiferromagnet in two-dimensional limit. Considering MnBi_{2}Te_{4} as model material, find it to demonstrate remarkable set thickness-dependent topological transitions. While single septuple layer block is topologically trivial ferromagnet, thicker films made an odd (even) number blocks are uncompensated (compensated) antiferromagnets,...
An interplay of spin–orbit coupling and intrinsic magnetism is known to give rise the quantum anomalous Hall topological magnetoelectric effects under certain conditions. Their realization could open access low power consumption electronics as well many fundamental phenomena like image magnetic monopoles, Majorana fermions others. Unfortunately, being realized very recently, these are only accessible at extremely temperatures lack appropriate materials that would enable temperature increase...
Quantum states of matter combining non-trivial topology and magnetism attract a lot attention nowadays; the special focus is on magnetic topological insulators (MTIs) featuring quantum anomalous Hall axion insulator phases. Feasibility many novel phenomena that \emph{intrinsic} TIs may host depends crucially our ability to engineer efficiently tune their electronic structures. Here, using angle- spin-resolved photoemission spectroscopy along with \emph{ab initio} calculations we report large...
The layered van der Waals antiferromagnet MnBi${}_{2}$Te${}_{4}$ has been predicted previously to realize the first intrinsic magnetic topological insulator. Here, authors report spin- and angle-resolved photoemission experiments for MnBi${}_{2}$Te${}_{4}$(0001) surface, revealing a surface state in bulk band gap providing evidence interplay between exchange interaction spin-orbit coupling electronic structure. thus constitutes promising candidate exploit of states order spintronic device concepts.
Abstract We study the surface crystalline and electronic structures of antiferromagnetic topological insulator MnBi 2 Te 4 using scanning tunneling microscopy/spectroscopy (STM/S), micro( μ )-laser angle-resolved photoemission spectroscopy (ARPES), density functional theory calculations. Our STM images reveal native point defects at that we identify as Bi antisites Mn substitutions. Bulk X-ray diffraction further evidences presence Mn-Bi intermixing. Overall, our characterizations suggest...
Ferromagnetic topological insulators exhibit the quantum anomalous Hall effect that might be used for high precision metrology and edge channel spintronics. In conjunction with superconductors, they could host chiral Majorana zero modes which are among contenders realization of qubits. Recently, it was discovered stable 2+ state Mn enables formation intrinsic magnetic A1B2C4 stoichiometry. However, first representative, MnBi2Te4, is antiferromagnetic 25 K N\'eel temperature strongly n-doped....
Graphene is one of the most promising materials for nanoelectronics owing to its unique Dirac cone-like dispersion electronic state and high mobility charge carriers. However, facilitate implementation graphene-based devices, an essential change structure, a creation band gap should controllably be done. Brought about by two fundamentally different mechanisms, sublattice symmetry breaking or induced strong spin-orbit interaction, appearance can drive graphene into narrow-gap semiconductor 2D...
In this work, we employed angle resolved photoemission spectroscopy (ARPES) to analyze the temperature dependent changes in electronic structure of first antiferromagnetic topological insulator MnBi2Te4 upon crossing Néel TN ≈ 25 K. We observed an exchange splitting bulk conduction band, which has a power law dependence on (1−T/T0)2β with onset T0 well matching measured TN. found evolution surface states integrated spectral weight vicinity Dirac point. Furthermore, additional quasi-2D state...
Abstract Modification of the gap at Dirac point (DP) in axion antiferromagnetic topological insulator $${\hbox {MnBi}}_2 {\hbox {Te}}_4$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub> <mml:mtext>MnBi</mml:mtext> <mml:mn>2</mml:mn> </mml:msub> <mml:mtext>Te</mml:mtext> <mml:mn>4</mml:mn> </mml:mrow> </mml:math> and its electronic spin structure have been studied by angle- spin-resolved photoemission spectroscopy (ARPES) under laser excitation various...
Recently discovered intrinsic antiferromagnetic topological insulator MnBi$_2$Te$_4$ presents an exciting platform for realization of the quantum anomalous Hall effect and a number related phenomena at elevated temperatures. An important characteristic making this material attractive applications is its predicted large magnetic gap Dirac point (DP). However, while early experimental measurements reported on DP gaps, recent studies claimed to observe gapless dispersion cone. Here, using...
Abstract Ferromagnetism is the collective alignment of atomic spins that retain a net magnetic moment below Curie temperature, even in absence external fields. Reducing this fundamental property into strictly two-dimensions was proposed metal-organic coordination networks, but thus far has eluded experimental realization. In work, we demonstrate extended, cooperative ferromagnetism feasible an atomically thin two-dimensional network, despite only ≈ 5% monolayer being composed Fe atoms. The...
With the discovery and first characterization of graphene, its potential for spintronic applications was recognized immediately. Since then, an active field research has developed trying to overcome practical hurdles. One most severe challenges is find appropriate interfaces between graphene ferromagnetic layers, which are granting efficient injection spin-polarized electrons. Here, we show that grown under conditions on Co(0001) demonstrates perfect structural properties simultaneously...
Using a first-principles Green's function approach we study magnetic properties of the binary tetradymite chalcogenides ${\mathrm{Bi}}_{2}{\mathrm{Se}}_{3}$, ${\mathrm{Bi}}_{2}{\mathrm{Te}}_{3}$, and ${\mathrm{Sb}}_{2}{\mathrm{Te}}_{3}$. The coupling between transition-metal impurities is long range, extends beyond quintuple layer, decreases with increasing number $d$ electrons per $3d$ atom. We find two main mechanisms for interaction in these materials: indirect exchange mediated by free...
Topological insulators are a promising class of materials for applications in the field spintronics. New perspectives this can arise from interfacing metal–organic molecules with topological insulator spin-momentum locked surface states, which be perturbed enhancing or suppressing spintronics-relevant properties such as spin coherence. Here we show results an angle-resolved photemission spectroscopy (ARPES) and scanning tunnelling microscopy (STM) study prototypical cobalt phthalocyanine...
Magnetic proximity effect at the interface between magnetic and topological insulators (MIs TIs) is considered to have great potential in spintronics as, principle, it allows realizing quantum anomalous Hall magneto-electric effects (QAHE TME). Although an out-of-plane magnetization induced a TI by was successfully probed experiments, first-principles calculations reveal that strong electrostatic mismatch abrupt MI/TI interfaces creates harmful trivial states rendering both QAHE TME...
The implementation of future graphene-based electronics is essentially restricted by the absence a band gap in electronic structure graphene. Options how to create reproducible and processing compatible manner are very limited at moment. A promising approach for graphene engineering introduce large-scale sublattice asymmetry. Using photoelectron diffraction spectroscopy we have demonstrated selective incorporation boron impurities into only one two sublattices. We shown that well-oriented on...
Abstract Materials that possess nontrivial topology and magnetism is known to exhibit exotic quantum phenomena such as the anomalous Hall effect. Here, we fabricate a novel magnetic topological heterostructure Mn 4 Bi 2 Te 7 /Bi 3 where multiple layers are inserted into topmost quintuple layer of original insulator . A massive Dirac cone (DC) with gap 40–75 meV at 16 K observed. By tracing temperature evolution, this shown gradually decrease increasing blunt transition from massless DC...
Combining robust magnetism, strong spin-orbit coupling and unique thickness-dependent properties of van der Waals crystals could enable new spintronics applications. Here, using density functional theory, we propose the (MnSb$_2$Te$_4$)$\cdot$(Sb$_2$Te$_3$)$_n$ family stoichiometric compounds that harbour multiple topologically-nontrivial magnetic phases. In groundstate, first three members family, i.e. MnSb$_2$Te$_4$, ($n=0$), MnSb$_4$Te$_7$, ($n=1$), MnSb$_6$Te$_{10}$, ($n=2$), are 3D...
Magnetic topological insulators (TIs) herald a wealth of applications in spin-based technologies, relying on the novel quantum phenomena provided by their properties. Particularly promising is (MnBi
Embedding foreign atoms or molecules in graphene has become the key approach its functionalization and is intensively used for tuning structural electronic properties. Here, we present an efficient method based on chemical vapor deposition large scale growth of boron-doped (B-graphene) Ni(111) Co(0001) substrates using carborane as precursor. It shown that up to 19 at. % boron can be embedded matrix a planar C-B sp(2) network formed. resistant air exposure widely retains structure metals....