In: Physical Review B, 2020, vol. 102, no. 16, p. 165136
We show that a metastable η-pairing superconducting phase can be induced by photodoping doublons and holes into a strongly repulsive fermionic Hubbard model. The doublon-hole condensate originates from an intrinsic doublon-hole exchange interaction and does not rely on the symmetry of the half-filled Hubbard model. It extends over a wide range of doublon densities and effective temperatures....
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In: Computer Physics Communications, 2020, vol. 257, no. 2020, p. 107484
The nonequilibrium dynamics of correlated many-particle systems is of interest in connection with pump–probe experiments on molecular systems and solids, as well as theoretical investigations of transport properties and relaxation processes. Nonequilibrium Green’s functions are a powerful tool to study interaction effects in quantum many-particle systems out of equilibrium, and to extract...
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In: Physical Review B, 2020, vol. 101, no. 16, p. 161107
We investigate the strong-field dynamics of a paramagnetic two-band Mott insulator using real-time dynamical mean-field theory. We demonstrate that strong electric fields can lead to a transient localization of electrons. This nonequilibrium quantum effect allows us to reveal specific signatures of local correlations in the time-resolved photoemission spectrum. In particular, we demonstrate...
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In: Physical Review B, 2020, vol. 101, no. 8, p. 085127
We investigate the effect of nonlocal interactions on the photodoped Mott insulating state of the two-dimensional Hubbard model using a nonequilibrium generalization of the dynamical cluster approximation. In particular, we compare the situation where the excitonic states are lying within the continuum of doublon-holon excitations to a setup where the excitons appear within the Mott gap. In...
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In: Physical Review B, 2019, vol. 100, no. 23, p. 235117
We study the dynamics of charge-transfer insulators after a photoexcitation using the three-band Emery model which is relevant for the description of cuprate superconductors. We provide a detailed derivation of the nonequilibrium extension of the multiband GW + EDMFT formalism and the corresponding downfolding procedure. The Peierls construction of the electron-light coupling is generalized...
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In: Nature Communications, 2019, vol. 10, no. 1, p. 5556
An elusive goal in the field of driven quantum matter is the induction of long-range order. Here, we propose a mechanism based on light-induced evaporative cooling of holes in a correlated fermionic system. Since the entropy of a filled narrow band grows rapidly with hole doping, the isentropic transfer of holes from a doped Mott insulator to such a band results in a drop of temperature....
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In: Physical Review Letters, 2019, vol. 123, no. 19, p. 193602
We perform an ab initio comparison between nonequilibrium dynamical mean-field theory and optical lattice experiments by studying the time evolution of double occupations in the periodically driven Fermi-Hubbard model. For off-resonant driving, the range of validity of a description in terms of an effective static Hamiltonian is determined and its breakdown due to energy absorption close to...
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In: Physical Review B, 2019, vol. 100, no. 15, p. 155130
We show that the recently proposed cooling-by-doping mechanism allows one to efficiently prepare interesting nonequilibrium states of the Hubbard model. Using nonequilibrium dynamical mean field theory and a particle-hole symmetric setup with dipolar excitations to full and empty bands we produce cold photodoped Mott insulating states with a sharp Drude peak in the optical conductivity, a ...
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In: Physical Review B, 2019, vol. 100, no. 4, p. 041111
We study the dynamics of charge transfer insulators after photoexcitation using the three-band Emery model and a nonequilibrium extension of Hartree-Fock + EDMFT (extended dynamical mean field theory) and GW + EDMFT. While the equilibrium properties are accurately reproduced by the Hartree-Fock treatment of the ligand bands, dynamical correlations are essential for a proper description of the...
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In: physica status solidi (b), 2019, vol. 256, no. 7, p. 1800469
A fast time propagation method for nonequilibrium Green's functions (NEGF) based on the generalized Kadanoff–Baym Ansatz (GKBA) is applied to a lattice system with a symmetry‐broken equilibrium phase, namely an excitonic insulator (EI). The adiabatic preparation of a correlated symmetry‐broken initial state from a Hartree– Fock wave function within GKBA is assessed by comparing with a...
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