A5000948726- Quantum and electron transport phenomena
- Physics of Superconductivity and Magnetism
- Strong Light-Matter Interactions
- Quantum many-body systems
- Quantum Information and Cryptography
- Mechanical and Optical Resonators
- Advanced Condensed Matter Physics
- Force Microscopy Techniques and Applications
- Particle Accelerators and Free-Electron Lasers
- Electronic and Structural Properties of Oxides
- Cold Atom Physics and Bose-Einstein Condensates
- Quantum optics and atomic interactions
- Integrated Circuits and Semiconductor Failure Analysis
- Magnetic and transport properties of perovskites and related materials
- Semiconductor materials and interfaces
- Structural Analysis of Composite Materials
- Molecular Junctions and Nanostructures
- Semiconductor materials and devices
- Photocathodes and Microchannel Plates
- Quantum Electrodynamics and Casimir Effect
- Advanced Chemical Physics Studies
- Particle accelerators and beam dynamics
- Microbial Community Ecology and Physiology
- Near-Field Optical Microscopy
- Topological Materials and Phenomena
Max Planck Institute for the Structure and Dynamics of Matter
2021-2024
RWTH Aachen University
2018-2024
Center for Free-Electron Laser Science
2021-2024
Universität Hamburg
2021-2024
Jülich Aachen Research Alliance
2020-2023
TU Wien
2009-2023
Justus-Liebig-Universität Gießen
2020
University of Vienna
2012
Texas Department of Transportation
1996
Office of Scientific and Technical Information
1996
The Hubbard model represents the fundamental for interacting quantum systems and electronic correlations. Using two-dimensional half-filled at weak coupling as a testing ground, we perform comparative study of comprehensive set state-of-the-art many-body methods. Upon cooling into its insulating antiferromagnetic ground state, hosts rich sequence distinct physical regimes with crossovers between high-temperature incoherent regime, an intermediate-temperature metallic low-temperature regime...
Abstract Optical driving of materials has emerged as a versatile tool to control their properties, with photo-induced superconductivity being among the most fascinating examples. In this work, we show that light or lattice vibrations coupled an electronic interband transition naturally give rise electron-electron attraction may be enhanced when underlying boson is driven into non-thermal state. We find phenomenon resonantly amplified tuning boson’s frequency close energy difference between...
Using a leading algorithmic implementation of the functional renormalization group (fRG) for interacting fermions on two-dimensional lattices, we provide detailed analysis its quantitative reliability Hubbard model. In particular, show that recently introduced multiloop extension fRG flow equations self-energy and two-particle vertex allows precise match with parquet approximation also lattice problems. The refinement respect to previous fRG-based computation schemes relies an accurate...
We present an implementation of a truncated unity parquet solver (TUPS) which solves the equations using form-factor basis for fermionic momenta. This way fluctuations from different scattering channels are treated on equal footing. The essentially linear scaling computational costs in number untruncated bosonic momenta allows us to treat system sizes up 76x76 discrete lattice momenta, unprecedented by previous unbiased methods that include frequency dependence vertex. With TUPS, we provide...
Quantum geometry has been identified as an important ingredient for the physics of quantum materials and especially flat-band systems, such moir\'e materials. On other hand, coupling between light matter is key importance across disciplines Floquet cavity engineering solids. Here we present fundamental relations light-matter Bloch wave functions, with a particular focus on materials, in which quenching electronic kinetic energy could allow one to reach limit strong more easily than highly...
Abstract Recent experimental advances enable the manipulation of quantum matter by exploiting nature light. However, paradigmatic exactly solvable models, such as Dicke, Rabi or Jaynes-Cummings models for quantum-optical systems, are scarce in corresponding solid-state, materials context. Focusing on long-wavelength limit light, here, we provide an model given a tight-binding chain coupled to single cavity mode via quantized version Peierls substitution. We show that perturbative expansions...
The hybridization between light and matter forms the basis to achieve cavity control over quantum materials. In this Letter we investigate a coupled chain of interacting spinless fermions by numerically exact solutions perturbative analytical expansions. We draw two important conclusions about such systems: (i) Specific fluctuations system play pivotal role in achieving entanglement matter; (ii) turn, light-matter is key ingredient modify electronic properties cavity. hypothesize that those...
We present and implement a self-consistent D$\Gamma$A approach for multi-orbital models ab initio materials calculations. It is applied to the one-band Hubbard model at various interaction strengths with without doping, two-band two largely different bandwidths, SrVO$_3$. The self-energy feedback reduces critical temperatures compared dynamical mean-field theory, even zero temperature in two-dimensions. Compared one-shot, non-self-consistent calculation non-local correlations are...
The parquet equations are a self-consistent set of for the effective two-particle vertex an interacting many-fermion system. application these to bulk models is, however, demanding due complex emergent momentum and frequency structure vertex. Here, we show how channel-decomposition by means truncated unities, which was developed in context functional renormalization group efficiently treat dependence, can be transferred equations. This leads significantly reduced numerical effort scaling...
In this work, the influence of tip geometry in scanning capacitance microscopy is investigated experimentally and theoretically on metal-oxide-semiconductor- (MOS) Schottky-type junctions gallium-arsenide (GaAs). Using a two-dimensional model we find that electric field around screened by surface states essential parameters entering versus voltage C(V) characteristics are doping level contact area only. contrast to that, from penetrates into semiconductor MOS-type junction, effects much...
Pump-probe experiments have suggested the possibility to control electronic correlations by driving infrared-active phonons with resonant midinfrared laser pulses. In this work we study two possible microscopic nonlinear electron-phonon interactions behind these observations, namely coupling of squared lattice displacement either density or double occupancy. We investigate whether photon-phonon quantized light in an optical cavity enables similar over correlations. first show that inside a...
Van der Waals (vdW) heterostructures host many-body quantum phenomena that can be tuned in situ using electrostatic gates. These gates are often microstructured graphite flakes naturally form plasmonic cavities, confining light discrete standing waves of current density due to their finite size. Their resonances typically lie the GHz - THz range, corresponding same $\mu$eV meV energy scale characteristic many effects materials they electrically control. This raises possibility built-in...
We present a novel mechanism for the transfer of orbital angular momentum from optical vortex beams to electronic quantum Hall states. Specifically, we identify robust contribution radial photocurrent in an annular graphene sample within regime that depends on vorticity light. Our findings offer fundamental insights into probing and manipulation coherence, with wide-ranging implications advancing coherent optoelectronics.
In this paper, the impact of tip radius on dopant profiling by scanning microwave microscopy is investigated. The cantilevers are very likely to erode in such measurements, and thus, a two-dimensional Poisson solver was used calculate lateral spatial resolution as function doping. Moreover, strong correlation between slope calibration curves diameter found. increases toward −0.5 saturates approaches values 150 nm, which agreement with experimental data obtained from microscopy.
Advances in the control of intense infrared light have led to striking discovery metastable superconductivity $\mathrm{K}_3\mathrm{C}_{60}$ at 100K, lasting more than 10 nanoseconds. Inspired by these experiments, we discuss possible mechanisms for long-lived, photo-induced above $T_{c}$. We analyze a minimal model optically-driven Raman phonons coupled inter-band electronic transitions. Using this model, develop microscopic mechanism photo-controlling pairing interaction displacively...
Optical driving of materials has emerged as a versatile tool to control their properties, with photo-induced superconductivity being among the most fascinating examples. In this work, we show that light or lattice vibrations coupled an electronic interband transition naturally give rise electron-electron attraction may be enhanced when underlying boson is driven into non-thermal state. We find phenomenon resonantly amplified tuning boson's frequency close energy difference between two bands....
We investigate Floquet engineering in a sawtooth chain -- minimal model hosting nearly flat band endowed with nontrivial quantum geometry coupled to driven surface polaritons. In this paradigmatic model, light-matter coupling is enabled by despite the vanishing velocity and curvature. show that light polarization finite momentum transfer polaritonic settings provide sufficient tunability flatten or unflatten bands, sometimes drastic structure modifications beyond what attainable laser pulses...
Engineering phases of matter in cavities requires effective light-matter coupling strengths that are on the same order magnitude as bare system energetics, coined ultra-strong regime. For models itinerant electron systems, which do not have discrete energy levels, a clear definition this regime is outstanding to date. Here we argue change electronic mass exceeding $10\%$ its value may serve such definition. We propose quantitative computational scheme for obtaining relation vacuum and show...
Selective excitation of vibrational modes using strong laser pulses has emerged as a powerful material engineering paradigm. However, to realize deterministic control over properties for device applications, it is desirable have an analogous scheme without drive, operating in thermal equilibrium. We here propose such equilibrium analog the light-driven paradigm, leveraging coupling between lattice degrees freedom and quantum fluctuations electric field THz micro-cavity. demonstrate this...
In this work, photocurrent (PC) spectra on GaAs measured by conductive atomic force microscope (AFM) tips are analyzed quantitatively. The measurements were carried out n-doped bulk samples as a function of excitation wavelength and tip bias. data compared to simulations employing two-dimensional self consistent POISSON SOLVER. It is found that the shape depletion zone below AFM strongly influenced bias surface potential, which leads clear difference between PC obtained with large area devices tips.
Abstract Optical driving of materials has emerged as a versatile tool to control their properties, with photo-induced superconductivity being among the most fascinating examples. In this work, we show that light or lattice vibrations coupled an electronic interband transition naturally give rise electron-electron attraction may be enhanced when underlying boson is driven into non-thermal state. We find phenomenon resonantly amplified tuning boson’s frequency close energy difference between...
In this work, an unusual low frequency behavior observed in scanning capacitance microscopy/spectroscopy on GaAs/Al2O3 junctions is investigated. Using a two-dimensional simulation, we show that the of capacitance—voltage curves can be explained through increased minority carrier concentration at to GaAs–Al2O3 interface and tip geometry effects nanoscale. An analytic approach estimate transition between high regime also given.