35 citations · 150 across the 22 of their papers we have counts for
25 papers
Ubiquitous topological materials protected by hidden partial symmetries
Lumen Eek, Xuelong Chen, Malte Röntgen +2
Symmetries play a crucial role in protecting the topological phases of insulators, ensuring the robustness of their surface states against perturbations. Traditionally, these symme…
Topology Obstructs Nodeless Excitons
Lumen Eek
Lowest-energy excitons are usually expected to have nodeless -like envelope wavefunctions. We show that band topology can obstruct this expectation. The exciton envelope wavefu…
Decorated electronic kagome lattice in twisted bilayer germanene
Dennis J. Klaassen, Rian A. M. Ligthart, Andrés R. Botello Mendez +10
Artificial kagome lattices provide a route to electronic flat bands, geometric frustration, and correlation driven phases, but their realization in atomically controlled two-dimens…
Emergent -type topology in a quasi-one-dimensional extended QWZ model
Zebedeus F. Osseweijer, Lumen Eek, Cristiane Morais Smith
We investigate the emergence of zero-dimensional topological end states in nanoribbons described by the Qi-Wu-Zhang (QWZ) model and its extensions with longer-range couplings. Whil…
Fractality-induced photonic topological insulators
Shuming Zhang, Zhaoxin Wu, Lumen Eek +2
Fractal lattices have recently emerged as a promising setting for topological wave physics, but in most realizations the topological character is inherited from externally engineer…
Universality of dimensional crossovers in topological insulators
Lumen Eek, Zeb Osseweijer, Cristiane Morais Smith
We investigate dimensional crossovers in minimal tight-binding models of three-dimensional (3D) topological insulators subject to geometric confinement. While thin films are common…
Topology of honeycomb nanoribbons revisited
Zebedeus F. Osseweijer, Lumen Eek, Harold J. W. Zandvliet +2
We present an in-depth study of end states in honeycomb nanoribbons, focusing on the interplay between nanoribbon termination, chiral symmetry, and complex next-nearest-neighbor ho…
Fragile topology for six-fold rotation symmetry indicated by the concentric Wilson loop spectrum
Xinyang Li, Lumen Eek, Jasper van Wezel +1
We investigate topological phase transitions for the Haldane and Kane-Mele model in a lattice with symmetry, which consists of triangles and hexagons arranged in a two-dimensi…
Enhanced spin-current generation in Dirac altermagnets through Klein tunneling
Tomas T. Osterholt, Lumen Eek, Cristiane Morais Smith +1
Altermagnets have recently emerged as a new platform for spintronics applications, offering spin-split electronic bands despite vanishing net magnetization. Here, we investigate sp…
Tensor-network methodology for real-space super-moiré excitons
Anouar Moustaj, Yitao Sun, Tiago V. C. Antão +2
Computing excitonic spectra in quasicrystal and super-moiré systems constitutes a formidable challenge due to the exceptional size of the excitonic Hilbert space. Here, we demonstr…
Real-Space Imaging of Moiré-Confined Excitons in Twisted Bilayer MoS
Laurens J. M. Westenberg, Lumen Eek, Jort D. Verbakel +8
Twisted two-dimensional semiconductors generate a moiré landscape that confines excitons (bound electron-hole pairs) into programmable lattices, offering routes to efficient light…
Electric field-induced spin-valley locking in twisted bilayer buckled honeycomb materials
Harold J. W. Zandvliet, Pantelis Bampoulis, Cristiane Morais Smith +1
A twisted honeycomb bilayer exhibits a moiré superstructure that is composed of a hexagonal arrangement of AB and BA stacked domains separated by domain boundaries. In the case of…
Twist-modulated magnetic interactions in bilayer van der Waals materials
Tomas T. Osterholt, D. O. Oriekhov, Lumen Eek +2
The ability to control magnetic interactions at the nanoscale is crucial for the development of next-generation spintronic devices and functional magnetic materials. In this work,…
Electric-field control of zero-dimensional topological states in ultranarrow germanene nanoribbons
Lumen Eek, Esra D. van 't Westende, Dennis J. Klaassen +3
Reversible, all-electric control of symmetry-protected zero-dimensional modes has been a long-standing goal. In buckled honeycomb lattices, a perpendicular field couples to the sta…
Emergence of Imaginary Time Crystals in the non-Hermitian Su-Schrieffer-Heeger model
E. Slootman, L. Eek, C. Morais Smith +1
Parity-time symmetry constrains the spectrum of non-Hermitian systems to be either real or come in complex conjugate pairs. The transition between a symmetry-preserving phase with…
Realization of a one-dimensional topological insulator in ultrathin germanene nanoribbons
Dennis J. Klaassen, Lumen A. G. Eek, Alexander N. Rudenko +9
Realizing a one-dimensional (1D) topological insulator and identifying the lower dimensional limit of two-dimensional (2D) behavior are crucial steps toward developing high-density…
Fractality-induced Topology
L. Eek, Z. F. Osseweijer, C. Morais Smith
Fractal geometries, characterized by self-similar patterns and non-integer dimensions, provide an intriguing platform for exploring topological phases of matter. In this work, we i…
Latent Haldane Models
Anouar Moustaj, Lumen Eek, Malte Rontgen +1
Latent symmetries, which materialize after performing isospectral reductions, have recently been shown to be instrumental in revealing novel topological phases in one-dimensional s…
Haldane model on the Sierpiński gasket
Zebedeus Osseweijer, Lumen Eek, Anouar Moustaj +2
We investigate the topological phases of the Haldane model on the Sierpiński gasket. As a consequence of the fractal geometry, multiple fractal gaps arise. Additionally, a flat ban…
Higher-order topology protected by latent crystalline symmetries
L. Eek, M. Röntgen, A. Moustaj +1
We demonstrate that rotation symmetry is not a necessary requirement for the existence of fractional corner charges in Cn-symmetric higher-order topological crystalline insulators.…
Emergent non-Hermitian models
Lumen Eek, Anouar Moustaj, Malte Röntgen +3
The Hatano-Nelson and the non-Hermitian Su-Schrieffer-Heeger model are paradigmatic examples of non-Hermitian systems that host non-trivial boundary phenomena. In this work, we use…
Topological edge and corner states in Bi fractals on InSb
R. Canyellas, Chen Liu, R. Arouca +10
Topological materials hosting metallic edges characterized by integer quantized conductivity in an insulating bulk have revolutionized our understanding of transport in matter. The…
Breaking and resurgence of symmetry in the non-Hermitian Su-Schrieffer-Heeger model in photonic waveguides
E. Slootman, W. Cherifi, L. Eek +4
Symmetry is one of the cornerstones of modern physics and has profound implications in different areas. In symmetry-protected topological systems, symmetries are responsible for pr…
Compact localized boundary states in a quasi-1D electronic diamond-necklace chain
S. N. Kempkes, P. Capiod, S. Ismaili +4
Zero-energy modes localized at the ends of one-dimensional (1D) wires hold great potential as qubits for fault-tolerant quantum computing. However, all the candidates known to date…