Impact ionization processes in the steady state of a driven Mott-insulating layer coupled to metallic leads

Sorantin, Max Erich; Dorda, Antonius; Held, Karsten; Arrigoni, Enrico

doi:10.1103/physrevb.97.115113

Cited by 29 publications

(23 citation statements)

References 48 publications

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“…Since both in the DC and AC field cases, the timedependent Hamiltonian is time-periodic, we can use the Floquet dynamical mean-field theory (FDMFT) to determine the NESSs. [32][33][34][36][37][38][39]41,43 The main idea of DMFT is to evaluate the electron Green's function and selfenergy by mapping the original lattice problem to an effective impurity problem. 44 An illustration of the DMFT self-consistency loop is presented in Fig.…”

Section: A Model and Methodsmentioning

confidence: 99%

How a dc Electric Field Drives Mott Insulators Out of Equilibrium

et al. 2018

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Out of equilibrium phenomena are a major issue of modern physics. In particular, correlated materials such as Mott insulators experience fascinating long-lived exotic states under a strong electric field. Yet, the origin of their destabilization by the electric field is not elucidated. Here we present a comprehensive study of the electrical response of canonical Mott insulators GaM_{4}Q_{8} (M=V, Nb, Ta, Mo; Q=S, Se) in the context of a microscopic theory of electrical breakdown where in-gap states allow for a description in terms of a two-temperature model. Our results show how the nonlinearities and the resistive transition originate from a massive creation of hot electrons under an electric field. These results give new insights for the control of the long-lived states reached under an electric field in these systems which has recently open the way to new functionalities used in neuromorphic applications.

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Section: A Model and Methodsmentioning

confidence: 99%

How a dc Electric Field Drives Mott Insulators Out of Equilibrium

et al. 2018

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“…Case i) means that a doublon with an initial kinetic energy larger than the gap lowers its energy and excites another electron across the bandgap which generates one doublon and one holon. 31,32 This process has been shown to be beneficial to the efficiency of correlated solar cells. 44,45 The second thermalization process ii) means that a low energy doublon gains kinetic energy through several scatterings with other doublons and holons until its kinetic energy exceeds the gap size.…”

Section: A Two Time-scale Relaxation Dynamicsmentioning

confidence: 99%

Quantum Boltzmann equation for strongly correlated systems: Comparison to dynamical mean field theory

et al. 2018

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We investigate the potential of a quantum Boltzmann equation without momentum conservation for description of strongly correlated electron systems out of equilibrium. In a spirit similar to dynamical mean field theory (DMFT), the momentum conservation of the electron-electron scattering is neglected, which yields a time-dependent occupation function for the equilibrium spectral function, even in cases where well-defined quasiparticles do not exist. The main assumption of this method is that the spectral function remains sufficiently rigid under the non-equilibrium evolution. We compare the result of the quantum Boltzmann equation to non-equilibrium DMFT simulations for the case of photo-carrier relaxation in Mott insulators, where processes on very different timescales emerge, i.e., impact ionization, intra-Hubbard-band thermalization, and full thermalization. Since quantum Boltzmann simulations without momentum conservation are computationally cheaper than non-equilibrium DMFT, this method allows the simulation of more complicated systems or devices, and to access much longer times. arXiv:1806.02570v2 [cond-mat.str-el]

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“…On the theory side, many fundamental properties of photo-doped insulators have been investigated and clarified in studies of simple model systems, such as the single-band Hubbard [7,8], Holstein-Hubbard [9] and t-J model [10,11]. This includes the effect of electronphonon and electron-spin interactions on the energy dissipation of photo-doped carriers [8,12], impact ionization [13,14], and the gap size dependence of the recombination time [7].…”

Section: Introductionmentioning

confidence: 99%

Photoenhanced excitonic correlations in a Mott insulator with nonlocal interactions

et al. 2020

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We investigate the effect of nonlocal interactions on the photo-doped Mott insulating state of the twodimensional 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 doublonholon excitations to a set-up where the excitons appear within the Mott gap. In the first case, the creation of nearest-neighbor doublon-holon pairs by excitations across the Mott gap results in enhanced excitonic correlations, but these excitons quickly decay into uncorrelated doublons and holons. In the second case, photoexcitation results in long-lived excitonic states. While in a low-temperature equilibrium state, excitonic features are usually not evident in single-particle observables such as the photoemission spectrum, we show that the photo-excited nonequilibrium system can exhibit in-gap states associated with the excitons. The comparison with exact-diagonalization results for small clusters allows us to identify the signatures of the excitons in the photo-emission spectrum.

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Impact ionization processes in the steady state of a driven Mott-insulating layer coupled to metallic leads

Cited by 29 publications

References 48 publications

How a dc Electric Field Drives Mott Insulators Out of Equilibrium

How a dc Electric Field Drives Mott Insulators Out of Equilibrium

Quantum Boltzmann equation for strongly correlated systems: Comparison to dynamical mean field theory

Photoenhanced excitonic correlations in a Mott insulator with nonlocal interactions

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