Publications (26)
Dielectric Engineering of Electronic Correlations in a van der Waals Heterostructure
Philipp Steinleitner, Philipp Merkl, Alexander Graf +10
Heterostructures of van der Waals bonded layered materials offer unique means to tailor dielectric screening with atomic-layer precision, opening a fertile field of fundamental res…
All-optical band structure reconstruction and onset of Landau quantization of Dirac fermions
Josef Riepl, Marc Aichner, Nikolai N. Mikhailov +6
The nature of relativistic electrons in solids depends on the precise shape of the underlying band structure. Prominently, symmetry-related mechanisms, such as the breaking of time…
Ultrafast two-dimensional field spectroscopy of terahertz intersubband saturable absorbers
Jürgen Raab, Christoph Lange, Jessica L. Boland +9
Intersubband (ISB) transitions in semiconductor multi-quantum well (MQW) structures are promising candidates for the development of saturable absorbers at terahertz (THz) frequenci…
Perspective on real-space nanophotonic field manipulation using non-perturbative light-matter coupling
Erika Cortese, Joshua Mornhinweg, Rupert Huber +2
The achievement of large values of the light-matter coupling in nanoengineered photonic structures can lead to multiple photonic resonances contributing to the final properties of…
Magnetic control of an exciton-polariton condensate in a van der Waals magnet
Heng Zhang, Niloufar Nilforoushan, Christian Weidgans +12
Quasiparticle condensates are among the most spectacular solid-state manifestations of quantum physics. Coupling macroscopic real-space wavefunctions to additional degrees of freed…
The 2D Materials Roadmap
Wencai Ren, Peter Bøggild, Joan Redwing +70
Over the past two decades, 2D materials have rapidly evolved into a diverse and expanding family of material platforms. Many members of this materials class have demonstrated their…
Subcycle videography of lightwave-driven Landau-Zener-Majorana transitions in graphene
Vincent Eggers, Giacomo Inzani, Manuel Meierhofer +14
Strong light fields have unlocked previously unthinkable possibilities to tailor coherent electron trajectories, engineer band structures and shape emergent phases of matter all-op…
Femtosecond photo-switching of interface polaritons in black phosphorus heterostructures
Markus A. Huber, Fabian Mooshammer, Markus Plankl +8
The possibility of hybridizing collective electronic motion with mid-infrared (mid-IR) light to form surface polaritons has made van der Waals layered materials a versatile platfor…
Quantifying nanoscale electromagnetic fields in near-field microscopy by Fourier demodulation analysis
Fabian Mooshammer, Markus A. Huber, Fabian Sandner +3
Confining light to sharp metal tips has become a versatile technique to study optical and electronic properties far below the diffraction limit. Particularly near-field microscopy…
Ultrafast transition between exciton phases in van der Waals heterostructures
Philipp Merkl, Fabian Mooshammer, Philipp Steinleitner +11
Heterostructures of atomically thin van der Waals bonded monolayers have opened a unique platform to engineer Coulomb correlations, shaping excitonic, Mott insulating, or supercond…
Tailored nano-antennas for directional Raman studies of individual carbon nanotubes
Nicola Paradiso, Fatemeh Yaghobian, Christoph Lange +4
We exploit the near field enhancement of nano-antennas to investigate the Raman spectra of otherwise not optically detectable carbon nanotubes (CNTs). We demonstrate that a top-dow…
Attosecond charge transfer in atomic-resolution scanning tunnelling microscopy
Simon Maier, Raffael Spachtholz, Katharina Glöckl +10
Electrons in atoms and molecules move on attosecond time scales. Deciphering their quantum dynamics in space and time calls for high-resolution microscopy at this speed. While scan…
Phase-locked multi-terahertz electric fields exceeding 13 MV/cm at 190 kHz repetition rate
Matthias Knorr, Jürgen Raab, Maximilian Tauer +6
We demonstrate a compact source of energetic and phase-locked multi-terahertz pulses at a repetition rate of 190 kHz. Difference frequency mixing of the fundamental output of an Yb…
Shot noise reduced terahertz detection via spectrally post-filtered electro-optic sampling
Michael Porer, Jean-Michel Ménard, Rupert Huber
In ultrabroadband terahertz electro-optic sampling, spectral filtering of the gate pulse can strongly reduce the quantum noise while the signal level is only weakly affected. The c…
Observation of an isolated flat band in the van der Waals crystal NbOCl
Changhua Bao, Vincent Eggers, Manuel Meierhofer +11
Dispersionless electronic bands lead to an extremely high density of states and suppressed kinetic energy, thereby increasing electronic correlations and instabilities that can sha…
Mapping of the dark exciton landscape in transition metal dichalcogenides
Gunnar Berghäuser, Philipp Steinleitner, Philipp Merkl +3
Transition metal dichalcogenides (TMDs) exhibit a remarkable exciton physics including optically accessible (bright) as well as spin- and momentum-forbidden (dark) excitonic states…
Light emission from gold nanoparticles under ultrafast near-infrared excitation: thermal emission, inelastic light scattering or multiphoton luminescence?
Lukas Roloff, Philippe Klemm, Imke Gronwald +3
Gold nanoparticles emit broad-band upconverted luminescence upon irradiation with pulsed infrared laser radiation. Although the phenomenon is widely observed, considerable disagree…
Terahertz light-matter interaction beyond unity coupling strength
Andreas Bayer, Marcel Pozimski, Simon Schambeck +4
Achieving control over light-matter interaction in custom-tailored nanostructures is at the core of modern quantum electrodynamics [1-15]. In ultrastrongly coupled systems [5-15],…
Probing of electromagnetic fields on atomic scale by photoelectric phenomena in graphene
Peter Olbrich, Christoph Drexler, Leonid E. Golub +8
We report on the observation of the reststrahl band assisted photocurrents in epitaxial graphene on SiC excited by infrared radiation. The peculiar spectral dependence for frequenc…
Giant Zeeman splitting inducing near-unity valley polarization in van der Waals heterostructures
Philipp Nagler, Mariana V. Ballottin, Anatolie A. Mitioglu +8
Monolayers of semiconducting transition metal dichalcogenides exhibit intriguing fundamental physics of strongly coupled spin and valley degrees of freedom for charge carriers. Whi…
Interferometric carrier-envelope phase stabilization for ultrashort pulses in the mid-infrared
Manuel Meierhofer, Simon Maier, Dmytro Afanasiev +3
We demonstrate an active carrier-envelope phase (CEP) stabilization scheme for optical waveforms generated by difference-frequency mixing of two spectrally detuned and phase-correl…
Momentum-resolved observation of exciton formation dynamics in monolayer WS
Robert Wallauer, Raul Perea-Causin, Lasse Münster +8
The dynamics of exciton formation in transition metal dichalcogenides is difficult to measure experimentally, since many momentum-indirect exciton states are not accessible to opti…
Rapid-scan acousto-optical delay line with 34 kHz scan rate and 15 attosecond precision
Olaf Schubert, Max Eisele, Vincent Crozatier +3
An optical fast-scan delay exploiting the near-collinear interaction between a train of ultrashort optical pulses and an acoustic wave propagating in a birefringent crystal is intr…
Broadband THz study of excitonic resonances in the high-density regime
Rupert Huber, Robert A. Kaindl, Ben A. Schmid +1
We report the first terahertz study of the intra-excitonic 1s-2p transition at high excitation densities in GaAs/AlGaAs quantum wells. A strong shift, broadening, and ultimately th…
Sculpting ultrastrong light-matter coupling through spatial matter structuring
Joshua Mornhinweg, Laura Diebel, Maike Halbhuber +6
The central theme of cavity quantum electrodynamics is the coupling of a single optical mode with a single matter excitation, leading to a doublet of cavity polaritons which govern…
Direct observation of ultrafast exciton formation in monolayer WSe
Philipp Steinleitner, Philipp Merkl, Philipp Nagler +5
Many of the fundamental optical and electronic properties of atomically thin transition metal dichalcogenides are dominated by strong Coulomb interactions between electrons and hol…