A5046713725- Laser-Matter Interactions and Applications
- Spectroscopy and Quantum Chemical Studies
- Advanced Fiber Laser Technologies
- Advanced Chemical Physics Studies
- Terahertz technology and applications
- Topological Materials and Phenomena
- Electronic and Structural Properties of Oxides
- Advanced Condensed Matter Physics
- Photorefractive and Nonlinear Optics
- Mechanical and Optical Resonators
- Quantum and electron transport phenomena
- Strong Light-Matter Interactions
- Physics of Superconductivity and Magnetism
- 2D Materials and Applications
- Mass Spectrometry Techniques and Applications
- Semiconductor materials and devices
- Organic and Molecular Conductors Research
- Magneto-Optical Properties and Applications
- Laser Material Processing Techniques
- Magnetic properties of thin films
- Laser-Plasma Interactions and Diagnostics
- Graphene research and applications
- Machine Learning in Materials Science
- Advanced Thermodynamics and Statistical Mechanics
- Semiconductor Quantum Structures and Devices
Max Planck Institute for the Structure and Dynamics of Matter
2016-2025
Center for Free-Electron Laser Science
2018-2025
Universität Hamburg
2018-2025
European Theoretical Spectroscopy Facility
2017-2025
Deutsches Elektronen-Synchrotron DESY
2019-2022
Max Planck Society
2018-2021
Laboratoire des Solides Irradiés
2015-2016
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2014-2016
École Polytechnique
2014-2016
Centre National de la Recherche Scientifique
2014-2015
An accurate analytic model describing the microscopic mechanism of high-harmonic generation (HHG) in solids is derived. Extensive first-principles simulations within a time-dependent density-functional framework corroborate conclusions model. Our results reveal that (i) emitted HHG spectra are highly anisotropic and laser-polarization dependent even for cubic crystals; (ii) harmonic emission enhanced by inhomogeneity electron-nuclei potential; yield increased heavier atoms; (iii) cutoff...
The strong ellipticity dependence of high-harmonic generation (HHG) in gases enables numerous experimental techniques that are nowadays routinely used, for instance, to create isolated attosecond pulses. Extending such solids requires a fundamental understanding the microscopic mechanism HHG. Here we use first-principles simulations within time-dependent density-functional framework and show how intraband interband mechanisms strongly differently affected by driving laser field. complex...
In a groundbreaking experimental advance it was recently shown that by stacking two sheets of graphene atop each other at twist angle close to one the so called "magic angles", an effective two-dimensional correlated system emerges. this kinetic energy low-energy electrons is much reduced and consequently interactions become very relevant, providing new platform into physics materials. Evidence proposed Mott insulating as well superconducting state in these highly tunable systems has spurred...
Over the last few years, extraordinary advances in experimental and theoretical tools have allowed us to monitor control matter at short time atomic scales with a high degree of precision. An appealing challenging route toward engineering materials tailored properties is find ways design or selectively manipulate materials, especially quantum level. To this end, having state-of-the-art ab initio computer simulation tool that enables reliable accurate light-induced changes physical chemical...
Nonlinear optical response from a van der Waals interface is modulated and enhanced in twistable boron nitride homostructures.
Engineering effective electronic parameters is a major focus in condensed matter physics. Their dynamical modulation opens the possibility of creating and controlling physical properties systems driven out equilibrium. In this Letter, we demonstrate that Hubbard U, widely used on-site Coulomb repulsion strongly correlated materials, can be modified on femtosecond timescales by strong nonresonant laser pulse excitation prototypical charge-transfer insulator NiO. Using our recently developed...
The generation of high-order harmonics from atomic and molecular gases enables the production high-energy photons ultrashort isolated pulses. Obtaining efficiently similar photon energy solid-state systems could lead, for instance, to more compact extreme ultraviolet soft x-ray sources. We demonstrate ab initio simulations that it is possible generate free-standing monolayer materials, with an cutoff gases. In limit in which electrons are driven by pump laser perpendicularly monolayer, they...
Superconductivity in organic conductors is often tuned by the application of chemical or external pressure. With this type tuning, orbital overlaps and electronic bandwidths are manipulated, whilst properties molecular building blocks remain virtually unperturbed.Here, we show that excitation local vibrations charge-transfer salt $\kappa-(BEDT-TTF)_2Cu[N(CN)_2]Br$ induces a colossal increase carrier mobility opening superconducting-like optical gap. Both features track density...
Generation of high-order harmonics in gases enabled to probe the attosecond electron dynamics atoms and molecules with unprecedented resolution. Extending techniques developed originally for atomic molecular solid state materials requires a fundamental understanding physics that has been partially addressed theoretically. Here we employ time-dependent density-functional theory investigate how resulting high-harmonic emission monolayer hexagonal boron nitride is affected by presence...
We demonstate a non-equilibrium route for ultrafast modification of Fermi surface topology in quantum materials.
Irradiating solids with ultrashort laser pulses is known to initiate femtosecond timescale magnetization dynamics. However, sub-femtosecond spin dynamics have not yet been observed or predicted. Here, we explore ultrafast light-driven in a highly non-resonant strong-field regime. Through state-of-the-art ab-initio calculations, predict that non-magnetic material can be transiently transformed into magnetic one via dynamical extremely nonlinear spin-flipping processes, which occur on...
High harmonic generation (HHG) has developed in recent years as a promising tool for ultrafast materials spectroscopy. At the forefront of these advancements, several works proposed using HHG an all-optical probe topology quantum matter by identifying its signatures emission spectra. However, it remains unclear if such spectral are indeed robust and general approach probing topology. To address this point, we perform fully ab initio study from prototypical two-dimensional topological...
Two-dimensional materials offer a versatile platform to study high-harmonic generation (HHG), encompassing as limiting cases bulklike and atomiclike harmonic [Tancogne-Dejean Rubio, Sci. Adv. 4, eaao5207 (2018)]. Understanding the response of few-layer semiconducting systems is important might open up possible technological applications. Using extensive first-principles calculations within time-dependent density functional theory framework, we show how in-plane out-of-plane nonlinear...
In this article, we propose an energy functional at the level of DFT+U+V that allows us to compute self-consistently values on-site interaction, Hubbard U and Hund J, as well intersite interaction V. This extends previously proposed ACBN0 [Phys. Rev. X 5, 011006 (2015)] including both interactions. We show ab initio self-consistent yields improved electronic properties for a wide range materials, ranging from $sp$ materials strongly-correlated materials. can also be seen alternative general...
We report on the generation of bulk photocurrents in materials driven by non-resonant bi-chromatic fields that are circularly polarized and co-rotating. The nonlinear have a fully controllable directionality amplitude without requiring carrier-envelope-phase stabilization or few-cycle pulses, generated with photon energies much smaller than band gap (reducing heating photo-conversion process). demonstrate ab-initio calculations photocurrent mechanism is universal arises gaped (Si, diamond,...
Quantum-electrodynamical density-functional theory (QEDFT) provides a promising avenue for exploring complex light-matter interactions in optical cavities real materials. Similar to conventional theory, the Kohn-Sham formulation of QEDFT needs approximations generally unknown exchange-correlation functional. In addition usual electron-electron potential, an approximation electron-photon potential is needed. A recent exchange functional [C. Schäfer , ], derived from equation motion...
We implemented various DFT+U schemes, including the ACBN0 self-consistent density-functional version of method [Phys. Rev. X 5, 011006 (2015)] within massively parallel real-space time-dependent density functional theory (TDDFT) code Octopus. further extended to case calculation response functions with real-time TDDFT+U and description non-collinear spin systems. The implementation is tested by investigating ground-state optical properties transition metal oxides, bulk topological...
On the basis of real-time ab initio calculations, we study non-perturbative interaction two-color laser pulses with MgO crystal in strong field regime to generate isolated attosecond pulse from high-harmonic emissions crystal. In this regard, examine impact incident characteristics such as its shape, intensity, and ellipticity well consequence anisotropy on emitted harmonics their corresponding pulses. Our calculations predict creation a duration ~ 300 attoseconds; addition, using elliptical...
High-order harmonic generation (HHG) from crystals is emerging as a new ultrashort source of coherent extreme ultraviolet (XUV) light. Doping the crystal structure can offer way to control properties. Here, we present study HHG enhancement in XUV spectral region an ionic crystal, using dopant-induced vacancy defects, driven by laser centered at wavelength 1.55 μm. Our numerical simulations based on solutions semiconductor Bloch equations and density-functional theory are supported our...
We investigate the low-temperature charge density wave (CDW) state of bulk TaS_{2} with a fully self-consistent density-functional theory Hubbard U potential, over which controversy has remained unresolved regarding out-of-plane metallic band. By examining innate structure we reveal that conventional use atomic-orbital basis could seriously misevaluate electron correlation in CDW state. adopting generalized basis, covering whole David star, successfully reproduce Mott insulating nature...
High harmonic generation (HHG) takes place in all phases of matter. In gaseous atomic and molecular media, it has been extensively studied is very well understood. solids, research ongoing, but a consensus forming for the dominant microscopic HHG mechanisms. liquids, on other hand, no established theory yet exists, approaches developed gases solids are generally inapplicable, hindering our current understanding. We develop here powerful reliable ab initio cluster-based approach describing...
Abstract High-harmonic spectroscopy is an all-optical nonlinear technique with inherent attosecond temporal resolution. It has been applied to a variety of systems in the gas phase and solid state. Here we extend its use liquid samples. By studying high-harmonic generation over broad range wavelengths intensities, show that cut-off energy independent wavelength beyond threshold intensity it characteristic property studied liquid. We explain these observations semi-classical model based on...
Abstract Polar crystals can be driven into collective oscillations by optical fields tuned to precise resonance frequencies. As the amplitude of excited phonon modes increases, novel processes scaling non-linearly with applied begin contribute dynamics atomic system. Here we show two such nonlinearities that are induced and enhanced strong in van der Waals crystal hexagonal boron nitride (hBN). We predict observe large sub-picosecond duration signals due four-wave mixing (FWM) during...
We propose exchanging the energy functionals in ground-state density-functional theory with physically equivalent exact force expressions as a new promising route toward approximations to exchange–correlation potential and energy. In analogy usual energy-based procedure, we split difference between interacting auxiliary Kohn–Sham system into Hartree, an exchange, correlation force. The corresponding scalar is obtained by solving Poisson equation, while additional transverse part of yields...