papers

Publications (27)

cond-mat.mes-hall2025

Intercalant-induced Kekule ordering and gap opening in quasi-free-standing graphene

Huu Thoai Ngo, Zamin Mamiyev, Niklas Witt +2

We present a comprehensive investigation of the structural and electronic properties of Sn intercalated buffer layers on SiC(0001) using low-temperature scanning tunneling microsco…

cond-mat.mes-hall2025

Inelastic tunneling into multipolaronic bound states in single-layer MoS

Camiel van Efferen, Laura Pätzold, Tfyeche Y. Tounsi +12

Polarons are quasiparticles that arise from the interaction of electrons or holes with lattice vibrations. Though polarons are well-studied across multiple disciplines, experimenta…

cond-mat.mtrl-sci2023

Phonon Self-Energy Corrections: To Screen, or Not to Screen

Jan Berges, Nina Girotto, Tim Wehling +2

First-principles calculations of phonons are often based on the adiabatic approximation and on Brillouin-zone samplings that might not always be sufficient to capture the subtletie…

cond-mat.mtrl-sci2021

A full gap above the Fermi level: the charge density wave of monolayer VS2

Camiel van Efferen, Jan Berges, Joshua Hall +15

In the standard model of charge density wave (CDW) transitions, the displacement along a single phonon mode lowers the total electronic energy by creating a gap at the Fermi level,…

cond-mat.str-el2019

Bandwidth renormalization due to the intersite Coulomb interaction

Yann in 't Veld, Malte Schüler, Tim Wehling +2

The theory of correlated electrons is currently moving beyond the paradigmatic Hubbard , towards the investigation of intersite Coulomb interactions. Recent investigations have…

cond-mat.str-el2026

Twisted Bilayer Graphene Lifetimes At Integer Fillings: An Analytic Result

Haoyu Hu, Yuelin Shao, Lorenzo Crippa +5

Twisted bilayer graphene near integer fillings hosts correlated single-particle excitations whose dispersion and linewidth are increasingly accessible experimentally. We study thes…

cond-mat.str-el2025

Ultrafast Electronic Structure Engineering in 1-TaS: Role of Doping and Amplitude Mode Dynamics

J. Jayabalan, Jiyu Chen, Laura Pätzold +12

In strongly correlated transition metal dichalcogenides, an intricate interplay of polaronic distortions, stacking arrangement, and electronic correlations determines the nature of…

cond-mat.mes-hall2013

Charge doping induced phase transitions in hydrogenated and fluorinated graphene

Tim Wehling, Bernhard Grundkötter-Stock, Bálint Aradi +2

We show that charge doping can induce transitions between three distinct adsorbate phases in hydrogenated and fluorinated graphene. By combining ab initio, approximate density func…

cond-mat.str-el2026

Moiré-induced symmetry breaking of charge order in van der Waals heterostructures

Sandra Sajan, Laura Pätzold, Tarushi Agarwal +10

Layered materials that stack different lattice symmetries are rare in nature. Misfit layered chalcogenides, which combine square and hexagonal lattices of rocksalt monochalcogenide…

cond-mat.str-el2023

Heterogeneous Ta-dichalcogenide bilayer: heavy fermions or doped Mott physics?

Lorenzo Crippa, Hyeonhu Bae, Paul Wunderlich +5

Controlling and understanding electron correlations in quantum matter is one of the most challenging tasks in materials engineering. In the past years a plethora of new puzzling co…

cond-mat.supr-con2025

Resolving Intervalley Gaps and Many-Body Resonances in Moiré Superconductor

Hyunjin Kim, Gautam Rai, Lorenzo Crippa +15

Magic-angle twisted multilayer graphene stands out as a highly tunable class of moiré materials that exhibit strong electronic correlations and robust superconductivity. However,…

cond-mat.str-el2026

Interplay between many-body correlations, strain and lattice relaxation in twisted bilayer graphene

Lorenzo Crippa, Gautam Rai, Dumitru Călugăru +6

In twisted bilayer graphene, a unified understanding of the mechanisms governing temperature-dependent electronic spectra and thermodynamic properties remains controversial despite…

cond-mat.str-el2025

Effective enhancement of the electron-phonon coupling driven by nonperturbative electronic density fluctuations

Emin Moghadas, Matthias Reitner, Tim Wehling +3

We present a dynamical mean-field study of the nonperturbative electronic mechanisms, which may lead to significant enhancements of the electron-phonon coupling in correlated elect…

cond-mat.str-el2026

Distinct lattice and charge excitations in AV3Sb5 kagome superconductors

Dongjin Oh, Stefan Enzner, Lennart Klebl +12

The kagome superconductor family AV3Sb5 (A=Cs, Rb, K) provides a rich platform for exploring diverse electronic symmetry breaking phenomena, including superconductivity and various…

cond-mat.str-el2024

Dynamical correlations and order in magic-angle twisted bilayer graphene

Gautam Rai, Lorenzo Crippa, Dumitru Călugăru +8

In magic angle twisted bilayer graphene, transport, thermodynamic and spectroscopic experiments pinpoint at a competition between distinct low-energy states with and without electr…

cond-mat.str-el2021

Efficient fluctuation exchange approach to low-temperature spin fluctuations and superconductivity: from the Hubbard model to NaCoOHO

Niklas Witt, Erik G. C. P. van Loon, Takuya Nomoto +2

Superconductivity arises mostly at energy and temperature scales that are much smaller than the typical bare electronic energies. Since the computational effort of diagrammatic man…

cond-mat.str-el2019

Turbulent hydrodynamics in strongly correlated Kagome metals

Domenico Di Sante, Johanna Erdmenger, Martin Greiter +6

A current challenge in condensed matter physics is the realization of strongly correlated, viscous electron fluids. These fluids are not amenable to the perturbative methods of Fer…

cond-mat.str-el2017

Electronic Structure of FeTe bulk crystals and epitaxial FeTe thin films on BiTe

Fabian Arnold, Jonas Warmuth, Matteo Michiardi +12

The electronic structure of thin films of FeTe grown on BiTe is investigated using angle-resolved photoemission spectroscopy, scanning tunneling microscopy and first princi…

cond-mat.mtrl-sci2025

Persistence of charge ordering instability to Coulomb engineering in the excitonic insulator candidate TiSe

Sebastian Buchberger, Yann in 't Veld, Akhil Rajan +11

TiSe has long been considered one of the best candidate materials to host the elusive excitonic insulator (EI) phase. However, a finite coupling to the lattice can generically…

cond-mat.str-el2023

Dynamics and Resilience of the Charge Density Wave in a bilayer kagome metal

Manuel Tuniz, Armando Consiglio, Denny Puntel +22

Long-range electronic order descending from a metallic parent state constitutes a rich playground to study the intricate interplay of structural and electronic degrees of freedom.…

cond-mat.str-el2023

Electronic correlations and universal long-range scaling in kagome metals

Domenico Di Sante, Bongjae Kim, Werner Hanke +4

We investigate the real-space profile of effective Coulomb interactions in correlated kagome materials. By particularizing to KVSb, CoSnS, FeSn, and NiIn, w…

cond-mat.str-el2021

Downfolding the Su-Schrieffer-Heeger model

Arne Schobert, Jan Berges, Tim Wehling +1

Charge-density waves are responsible for symmetry-breaking displacements of atoms and concomitant changes in the electronic structure. Linear response theories, in particular densi…

cond-mat.mes-hall2023

Unconventional charge-density-wave gap in monolayer NbS

Timo Knispel, Jan Berges, Arne Schobert +5

Using scanning tunneling microscopy and spectroscopy, for a monolayer of transition metal dichalcogenide H-NbS grown by molecular beam epitaxy on graphene, we provide unambiguo…

cond-mat.mes-hall2015

Proximity Enhanced Quantum Spin Hall State in Graphene

Liangzhi Kou, Feiming Hu, Binghai Yan +4

Graphene is the first model system of two-dimensional topological insulator (TI), also known as quantum spin Hall (QSH) insulator. The QSH effect in graphene, however, has eluded d…

cond-mat.str-el2016

Manifestation of nonlocal electron-electron interaction in graphene

Søren Ulstrup, Malte Schüler, Marco Bianchi +5

Graphene is an ideal platform to study many-body effects due to its semimetallic character and the possibility to dope it over a wide range. Here we study the width of graphene's o…

cond-mat.mtrl-sci2026

Femtosecond concerted rotation of molecules on a 2D material interface

Kiana Baumgärtner, Misa Nozaki, Marvin Reuner +20

Interfaces between molecules and 2D materials exhibit energy-driven functionalities, wherein charge transfer directs molecular motion. Unlike equilibrium systems, where molecular a…

cond-mat.mtrl-sci2015

Correlated electron behavior of metalorganic molecules: insights from density functional theory combined with many-body effects using exact diagonalization

Sumanta Bhandary, Malte Schüler, Patrik Thunström +5

A proper theoretical description of electronic structure of the 3d orbitals in the metal centers of functional metalorganics is a challenging problem. In this letter, we apply dens…