A5087474630- Physics of Superconductivity and Magnetism
- Advanced Condensed Matter Physics
- Magnetic and transport properties of perovskites and related materials
- Quantum and electron transport phenomena
- Cold Atom Physics and Bose-Einstein Condensates
- Theoretical and Computational Physics
- Rare-earth and actinide compounds
- Quantum many-body systems
- Electronic and Structural Properties of Oxides
- Iron-based superconductors research
- Quantum, superfluid, helium dynamics
- Organic and Molecular Conductors Research
- Advanced Chemical Physics Studies
- Spectroscopy and Quantum Chemical Studies
- Advanced Thermodynamics and Statistical Mechanics
- High-pressure geophysics and materials
- 2D Materials and Applications
- Stochastic processes and statistical mechanics
- Quantum Information and Cryptography
- Topological Materials and Phenomena
- Material Dynamics and Properties
- Magnetic properties of thin films
- Complex Systems and Time Series Analysis
- Magnetic Properties of Alloys
- Machine Learning in Materials Science
Collège de France
2016-2025
Flatiron Health (United States)
2018-2025
Flatiron Institute
2018-2025
University of Geneva
2016-2025
Centre de Physique Théorique
2016-2025
Centre National de la Recherche Scientifique
2015-2024
École Polytechnique
2015-2024
Centre de Physique Théorique
2015-2024
Université Paris Sciences et Lettres
1995-2024
Simons Foundation
2019-2023
We review the dynamical mean-field theory of strongly correlated electron systems which is based on a mapping lattice models onto quantum impurity subject to self-consistency condition. This exact for electrons in limit large coordination (or infinite spatial dimensions). It extends standard construction from classical statistical mechanics problems. discuss physical ideas underlying this and its mathematical derivation. Various analytic numerical techniques that have been developed recently...
We present an exact mapping of the Hubbard model in infinite dimensions onto a single-impurity Anderson (or Wolff) supplemented by self-consistency condition. This provides mean-field picture strongly corrrelated systems, which becomes as d\ensuremath{\rightarrow}\ensuremath{\infty}. point out special integrable case equations, and study general using perturbative renormalization group around atomic limit. Three distinct Fermi-liquid regimes arise, corresponding to Kondo, mixed-valence,...
Strong electronic correlations are often associated with the proximity of a Mott-insulating state. In recent years however, it has become increasingly clear that Hund’s rule coupling (intra-atomic exchange) is responsible for strong in multiorbital metallic materials not close to Mott insulator. two effects: It influences energetics gap and strongly suppresses coherence scale formation Fermi liquid. A global picture emerged recently, which emphasizes importance average occupancy shell as...
We propose a systematic procedure for constructing effective models of strongly correlated materials. The parameters, in particular the on-site screened Coulomb interaction $U$, are calculated from first principles, using random-phase approximation. derive an expression frequency-dependent $U(\ensuremath{\omega})$ and show, case nickel, that its high-frequency part has significant influence on spectral functions. scheme taking into account energy dependence $U(\ensuremath{\omega})$, so model...
A theory of the metal-insulator transition in vanadium dioxide from high- temperature rutile to low- monoclinic phase is proposed on basis cluster dynamical mean-field theory, conjunction with density functional scheme. The interplay strong electronic Coulomb interactions and structural distortions, particular, dimerization atoms low-temperature phase, plays a crucial role. We find that ${\mathrm{V}\mathrm{O}}_{2}$ not conventional Mott insulator, but formation V-V singlet pairs due...
Femtosecond time-resolved photoemission is used to investigate the time evolution of electronic structure in Mott insulator 1T-TaS2. A collapse gap observed within 100 femtoseconds after optical excitation. The spectra and spectral function calculated by dynamical mean field theory show that this insulator-metal transition driven solely hot electrons. coherently excited lattice displacement results a periodic shift lasting for 20 ps without perturbing insulating phase. This capability...
Using ${t}_{2g}$ Wannier functions, a low-energy Hamiltonian is derived for orthorhombic $3{d}^{1}$ transition-metal oxides. Electronic correlations are treated with new implementation of dynamical mean-field theory noncubic systems. Good agreement photoemission data obtained. The interplay correlation effects and cation covalency (${\mathrm{GdFeO}}_{3}$-type distortions) found to suppress orbital fluctuations in ${\mathrm{LaTiO}}_{3}$ even more ${\mathrm{YTiO}}_{3}$, favor the transition...
We compute the thermodynamic properties of Sachdev-Ye-Kitaev (SYK) models fermions with a conserved fermion number, $\mathcal{Q}$. extend previously proposed Schwarzian effective action to include phase field, and this describes low temperature energy $\mathcal{Q}$ fluctuations. obtain higher-dimensional generalizations SYK which display disordered metallic states without quasiparticle excitations, we deduce their thermoelectric transport coefficients. also examine corresponding...
We present an approach that combines the local-density approximation (LDA) and dynamical mean-field theory (DMFT) in framework of full-potential linear augmented plane-wave method. Wannier-type functions for correlated shell are constructed by projecting local orbitals onto a set Bloch eigenstates located within certain energy window. The screened Coulomb interaction Hund's coupling calculated from first-principles constrained random-phase scheme. apply this $\text{LDA}+\text{DMFT}$...
We show that in multiband metals the correlations are strongly affected by Hund's rule coupling, which depending on filling promotes metallic, insulating or bad-metallic behavior. The quasiparticle coherence and proximity to a Mott insulator influenced distinctly and, away from single- half-filling, opposite ways. A correlated bad metal far phase is found there. propose concise classification of $3d$ $4d$ transition-metal oxides within ubiquitous occurrence strong Ru- Cr-based oxides, as...
Thermoelectric effects, such as the generation of a particle current by temperature gradient, have their origin in reversible coupling between heat and flows. These effects are fundamental probes for materials applications to cooling power generation. Here we demonstrate thermoelectricity fermionic cold atoms channel, ballistic or diffusive, connected two reservoirs. We show that magnitude effect efficiency energy conversion can be optimized controlling geometry disorder strength. Our...
We calculate the electronic structure of Sr(2)RuO(4), treating correlations within dynamical mean-field theory. The approach successfully reproduces several experimental results and explains key properties this material: anisotropic mass renormalization quasiparticles crossover into an incoherent regime above a low temperature scale. While orbital differentiation originates from proximity van Hove singularity, strong are caused by Hund's coupling. generality mechanism for other correlated...
We present a microscopic theory for ultrafast control of solids with high-intensity terahertz frequency optical pulses. When resonant selected infrared-active vibrations, these pulses transiently modify the crystal structure and lead to new collective electronic properties. The predicts dynamical path taken by lattice using first-principles calculations energy surface classical equations motion, as well symmetry considerations. Two classes dynamics are identified. In perturbative regime,...
We investigate transport in strongly correlated metals. Within dynamical mean-field theory, we calculate the resistivity, thermopower, optical conductivity and thermodynamic properties of a hole-doped Mott insulator. Two well-separated temperature scales are identified: ${T}_{\mathrm{FL}}$ below which Landau Fermi liquid behavior applies, ${T}_{\mathrm{MIR}}$ above resistivity exceeds Mott-Ioffe-Regel value bad-metal is found. show that quasiparticle excitations remain well defined dominate...
The Sachdev-Ye-Kitaev (SYK) model is a solvable of many-body quantum system that has stimulated interest in both condensed matter physics and gravity. This review focuses on the insights provided by SYK model, which no quasiparticle excitations, into Planckian non-Fermi-liquid metals. discussed for range strongly correlated models relation to experiments materials. Also included discussion recent developments regarding connections between theory black holes.
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...
The continued development of computational approaches to many-body ground-state problems in physics and chemistry calls for a consistent way assess its overall progress. In this work, we introduce metric variational accuracy, the V-score, obtained from energy variance. We provide an extensive curated dataset calculations quantum systems, identifying cases where state-of-the-art numerical show limited accuracy future algorithms or platforms, such as computing, could improved accuracy. V-score...
We propose a dynamical mean field approach for calculating the electronic structure of strongly correlated materials from first principles. The scheme combines GW method with theory, which enables one to treat strong interaction effects. It avoids conceptual problems inherent conventional ``LDA+DMFT'', such as Hubbard parameters and double counting terms. apply simplified version nickel find encouraging results.
We report conductivity measurements of Cr-doped V2O3 using a variable pressure technique. The critical behavior the near Mott-insulator to metal endpoint is investigated in detail as function and temperature. exponents are determined, well scaling associated with equation state. universal properties liquid-gas transition found. This potentially generic description Mott correlated electron materials.
The multiorbital Hubbard model is expressed in terms of quantum phase variables (``slave rotors'') conjugate to the local charge, and auxiliary fermions, providing an economical representation Hilbert space strongly correlated systems. When are treated a mean-field manner, similar results dynamical theory obtained, namely Brinkman-Rice transition at commensurate fillings together with ``preformed'' Mott gap single-particle density states. slave-rotor formalism allows go beyond description...