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View article: Synchrotron Radiation for Quantum Technology
Synchrotron Radiation for Quantum Technology Open
In recent years, quantum technology has undergone transformative advancements, opening up unprecedented possibilities in computation, metrology, sensing, and communication and reshaping the landscape of scientific research. Based on superp…
View article: Revealing the 1D Nature of Electronic States in Phosphorene Chains
Revealing the 1D Nature of Electronic States in Phosphorene Chains Open
Phosphorene, a 2D allotrope of phosphorus, is technologically very appealing because of its semiconducting properties and narrow bandgap. Further reduction of the phosphorene dimensionality may spawn exotic properties of its electronic str…
View article: Reviving Nitrogen-Vacancy Centers in Diamond via Local Surface Modification
Reviving Nitrogen-Vacancy Centers in Diamond via Local Surface Modification Open
Surface termination of semiconductors is important for their applications in electronics because it governs electrical properties at interfaces. For quantum sensors and qubits based on spins in solids, this is crucial when they are located…
View article: Nodeless Hybridization as Proof of Trivial Topology in Samarium Hexaboride
Nodeless Hybridization as Proof of Trivial Topology in Samarium Hexaboride Open
Calculations unanimously predict samarium hexaboride to be a topological Kondo insulator, the first topological insulator driven by strong electron correlation. As of today it appears also experimentally established as the only representat…
View article: Halide Perovskites as Spin-1 Dirac Materials
Halide Perovskites as Spin-1 Dirac Materials Open
Halide perovskites are a promising class of materials for optoelectronic and photovoltaic applications, exhibiting high power conversion efficiency due to strong light absorption and long carrier diffusion lengths. While various aspects of…
View article: Angle-resolved photoemission of topological materials
Angle-resolved photoemission of topological materials Open
Topological materials have gained significant attention in condensed matter physics due to their unique electronic and transport properties. Three-dimensional (3D) topological materials are characterized by robust electronic states that ar…
View article: Orbital-selective effect of spin reorientation on the Dirac fermions in a non-charge-ordered kagome ferromagnet Fe$_3$Ge
Orbital-selective effect of spin reorientation on the Dirac fermions in a non-charge-ordered kagome ferromagnet Fe$_3$Ge Open
Kagome magnets provide a fascinating platform for the realization of correlated topological quantum phases under various magnetic ground states. However, the effect of the magnetic spin configurations on the characteristic electronic struc…
View article: Lifshitz transition in titanium carbide driven by a graphene overlayer
Lifshitz transition in titanium carbide driven by a graphene overlayer Open
Two-dimensional (2D) Dirac materials are electronically and structurally very sensitive to proximity effects. We demonstrate, however, the opposite effect: that the deposition of a monolayer 2D material could exercise a substantial influen…
View article: One-dimensional electronic structure of phosphorene chains
One-dimensional electronic structure of phosphorene chains Open
Phosphorene, a 2D allotrope of phosphorus, is technologically very appealing because of its semiconducting properties and narrow band gap. Further reduction of the phosphorene dimensionality may spawn exotic properties of its electronic st…
View article: Search for ferromagnetism in Mn-doped lead halide perovskites
Search for ferromagnetism in Mn-doped lead halide perovskites Open
Lead halide perovskites are new key materials in various application areas such as high efficiency photovoltaics, lighting, and photodetectors. Doping with Mn, which is known to enhance the stability, has recently been reported to lead to …
View article: Suppression of nematicity by tensile strain in multilayer FeSe/SrTiO$_3$ films
Suppression of nematicity by tensile strain in multilayer FeSe/SrTiO$_3$ films Open
The nematicity in multilayer FeSe/SrTiO$_3$ films has been previously suggested to be enhanced with decreasing film thickness. Motivated by this, there have been many discussions about the competing relation between nematicity and supercon…
View article: Is there a polaron signature in angle-resolved photoemission of CsPbBr₃?
Is there a polaron signature in angle-resolved photoemission of CsPbBr₃? Open
The formation of large polarons has been proposed as reason for the high defect tolerance, low mobility, low charge carrier trapping and low nonradiative recombination rates of lead halide perovskites. Recently, direct evidence for large-p…
View article: Robust behavior and spin-texture stability of the topological surface state in Bi2Se3 upon deposition of gold
Robust behavior and spin-texture stability of the topological surface state in Bi2Se3 upon deposition of gold Open
The Dirac point of a topological surface state (TSS) is protected against gapping by time-reversal symmetry. Conventional wisdom stipulates, therefore, that only through magnetisation may a TSS become gapped. However, non-magnetic gaps hav…
View article: Probing the magnetic band gap of the ferromagnetic topological insulator MnSb$_2$Te$_4$
Probing the magnetic band gap of the ferromagnetic topological insulator MnSb$_2$Te$_4$ Open
Mn-rich MnSb$_2$Te$_4$ is a ferromagnetic topological insulator with yet the highest Curie temperature T_C = 45-50 K. It exhibits a magnetic gap at the Dirac point of the topological surface state that disappears above T_C. By scanning tun…
View article: On the problem of Dirac cones in fullerenes on gold
On the problem of Dirac cones in fullerenes on gold Open
There are Dirac cone-like features in ARPES spectra of C 60 on Au(111). We argue that their origin is not artificial graphene, but umklapp diffraction of surface electronic bands of Au on the molecular grid of C 60 in the final state of ph…
View article: Magnetization relaxation and search for the magnetic gap in bulk-insulating V-doped (Bi, Sb)2Te3
Magnetization relaxation and search for the magnetic gap in bulk-insulating V-doped (Bi, Sb)2Te3 Open
V-doped (Bi,Sb)2Te3 has a ten times higher magnetic coercivity than its Cr-doped counterpart and, therefore, is believed to be advantageous for the quantum anomalous Hall effect (QAHE). The QAHE requires the opening of a magnetic bandgap a…
View article: Mn‐Rich MnSb<sub>2</sub>Te<sub>4</sub>: A Topological Insulator with Magnetic Gap Closing at High Curie Temperatures of 45–50 K
Mn‐Rich MnSb<sub>2</sub>Te<sub>4</sub>: A Topological Insulator with Magnetic Gap Closing at High Curie Temperatures of 45–50 K Open
Ferromagnetic topological insulators exhibit the quantum anomalous Hall effect, which is potentially useful for high‐precision metrology, edge channel spintronics, and topological qubits. The stable 2+ state of Mn enables intrinsic magneti…
View article: Structure Inversion Asymmetry and Rashba Effect in Quantum Confined Topological Crystalline Insulator Heterostructures
Structure Inversion Asymmetry and Rashba Effect in Quantum Confined Topological Crystalline Insulator Heterostructures Open
Structure inversion asymmetry is an inherent feature of quantum confined heterostructures with non‐equivalent interfaces. It leads to a spin splitting of the electron states and strongly affects the electronic band structure. The effect is…
View article: Angle‐Resolved Photoemission of Topological Matter: Examples from Magnetism, Electron Correlation, and Phase Transitions
Angle‐Resolved Photoemission of Topological Matter: Examples from Magnetism, Electron Correlation, and Phase Transitions Open
Topological materials promise new functionalities, which are revealed with the help of angle‐resolved photoemission. Herein, the search for the magnetic bandgap at the Dirac point as a precondition for the quantum anomalous Hall effect is …
View article: Electrical Transport Properties of Vanadium‐Doped Bi<sub>2</sub>Te<sub>2.4</sub>Se<sub>0.6</sub>
Electrical Transport Properties of Vanadium‐Doped Bi<sub>2</sub>Te<sub>2.4</sub>Se<sub>0.6</sub> Open
Vanadium‐doped Bi 2– x Te 2.4 Se 0.6 single crystals, with x = 0.015 and 0.03, are grown by the Bridgman method. Bandstructure characterization by angle‐resolved photoemission spectroscopy (ARPES) measurements shows gapless topological sur…
View article: Effective mass enhancement and ultrafast electron dynamics of Au(111) surface state coupled to a quantum well
Effective mass enhancement and ultrafast electron dynamics of Au(111) surface state coupled to a quantum well Open
We show that, although the equilibrium band dispersion of the Shockley-type surface state of two-dimensional Au(111) quantum films grown on W(110) does not deviate from the expected free-electron-like behavior, its nonequilibrium energy-mo…
View article: Contrast Reversal in Scanning Tunneling Microscopy and Its Implications for the Topological Classification of SmB<sub>6</sub>
Contrast Reversal in Scanning Tunneling Microscopy and Its Implications for the Topological Classification of SmB<sub>6</sub> Open
SmB 6 has recently attracted considerable interest as a candidate for the first strongly correlated topological insulator. Such materials promise entirely new properties such as correlation‐enhanced bulk bandgaps or a Fermi surface from sp…
View article: Topological band crossings in epitaxial strained SnTe
Topological band crossings in epitaxial strained SnTe Open
Epitaxial SnTe (111) is grown by molecular-beam epitaxy on Bi2Te3 substrates. Structural evaluation indicates that SnTe deviates from cubic due to in-plane compressive strain, which induces significant changes in the electronic band struct…
View article: Samarium hexaboride is a trivial surface conductor
Samarium hexaboride is a trivial surface conductor Open
SmB6 is predicted to be the first member of the intersection of topological insulators and Kondo insulators, strongly correlated materials in which the Fermi level lies in the gap of a many-body resonance that forms by hybridization betwee…
View article: Extremely flat band in bilayer graphene
Extremely flat band in bilayer graphene Open
In both experiment and theory, we demonstrate a novel mechanism of flattened band formation in a honeycomb lattice bilayer.
View article: A consistent view of the samarium hexaboride terminations to resolve the nature of its surface states
A consistent view of the samarium hexaboride terminations to resolve the nature of its surface states Open
The research effort prompted by the prediction that SmB$_6$ could be the first topological Kondo insulator has produced a wealth of new results, though not all of these seem compatible. A major discrepancy exists between scanning tunneling…
View article: Band Renormalization of Blue Phosphorus on Au(111)
Band Renormalization of Blue Phosphorus on Au(111) Open
Most recently, theoretical calculations predicted the stability of a novel two-dimensional phosphorus honeycomb lattice named blue phosphorus. Here, we report on the growth of blue phosphorus on Au(111) and unravel its structural details u…