Coexistence of excited polarons and metastable delocalized states in photoinduced metals

Sayyad, Sharareh; Eckstein, Martin

doi:10.1103/physrevb.91.104301

Cited by 29 publications

(34 citation statements)

References 56 publications

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“…Note that the same problem, albeit with slightly different initial states and in the limit of an infinite coordination number, has very recently been studied by Sayyad and Eckstein using a nonequilibrium DMFT method [70]. Their main interest is in the adiabatic regime of phonon frequencies and in an extended analysis of photoemission spectra.…”

Section: Introductionmentioning

confidence: 97%

Real-time decay of a highly excited charge carrier in the one-dimensional Holstein model

et al. 2015

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We study the real-time dynamics of a highly excited charge carrier coupled to quantum phonons via a Holstein-type electron-phonon coupling. This is a prototypical example for the nonequilibrium dynamics in an interacting many-body system where excess energy is transferred from electronic to phononic degrees of freedom. We use diagonalization in a limited functional space (LFS) to study the nonequilibrium dynamics on a finite one-dimensional chain. This method agrees with exact diagonalization and the time-evolving block-decimation method, in both the relaxation regime and the long-time stationary state, and among these three methods it is the most efficient and versatile one for this problem. We perform a comprehensive analysis of the time evolution by calculating the electron, phonon and electron-phonon coupling energies, and the electronic momentum distribution function. The numerical results are compared to analytical solutions for short times, for a small hopping amplitude and for a weak electron-phonon coupling. In the latter case, the relaxation dynamics obtained from the Boltzmann equation agrees very well with the LFS data. We also study the time dependence of the eigenstates of the single-site reduced density matrix, which defines the so-called optimal phonon modes. We discuss their structure in nonequilibrium and the distribution of their weights. Our analysis shows that the structure of optimal phonon modes contains very useful information for the interpretation of the numerical data.

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Section: Introductionmentioning

confidence: 97%

Real-time decay of a highly excited charge carrier in the one-dimensional Holstein model

et al. 2015

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“…[31] showed that for weak nearest-neighbor interaction V the integral over the bosonic Weiss field scales as dωIm[D(ω)] ∝ V 2 . Hence our phenomenological analysis shows that the enhancement of the relaxation due to the nonlocal interaction V and the corresponding V 2 scaling is consistent with a relaxation aided by the coupling to a bath of bosonic degrees of freedom (plasmons) [36,[43][44][45][46].…”

Section: B Enhanced Doublon Relaxation Due To Dynamical Screeningmentioning

confidence: 99%

Dynamics of screening in photodoped Mott insulators

2015

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We use a nonequilibrium implementation of extended dynamical mean-field theory in combination with a noncrossing approximation impurity solver to study the effect of dynamical screening in photoexcited Mott insulators. The insertion of doublons and holes adds low-energy screening modes and leads to a reduction of the Mott gap. The coupling to low-energy bosonic modes furthermore opens new relaxation channels and significantly speeds up the thermalization process. We also investigate the effect of the energy distribution of the photo doped carriers on the screening.

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“…Deep in the Mott phase the number of holon-doublon pairs is an almost conserved quantity on the timescale of the electronic hopping, and the initial relaxation of the photo carriers can only occur within the Hubbard bands. The corresponding relaxation time strongly depends on the coupling of the photo-doped carriers to bosonic degrees of freedom, such as spins 24,25 or phonons [26][27][28][29][30] . In particular the scattering with antiferromagnetically ordered spins provides a very efficient cooling mechanism 14,24,31,32 .…”

Section: Introductionmentioning

confidence: 99%

Hund's coupling driven photocarrier relaxation in the two-band Mott insulator

et al. 2017

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We study the relaxation dynamics of photo-carriers in the paramagnetic Mott insulating phase of the half-filled two-band Hubbard model. Using nonequilibrium dynamical mean field theory, we excite charge carriers across the Mott gap by a short hopping modulation, and simulate the evolution of the photo-doped population within the Hubbard bands. We observe an ultrafast charge-carrier relaxation driven by emission of local spin excitations with an inverse relaxation time proportional to the Hund's coupling. The photo-doping generates additional side-bands in the spectral function, and for strong Hund's coupling, the photo-doped population also splits into several resonances. The dynamics of the local many-body states reveals two effects, thermal blocking and kinetic freezing, which manifest themselves when the Hund's coupling becomes of the order of the temperature or the bandwidth, respectively. These effects, which are absent in the single-band Hubbard model, should be relevant for the interpretation of experiments on correlated materials with multiple active orbitals. In particular, the features revealed in the non-equilibrium energy distribution of the photocarriers are experimentally accessible, and provide information on the role of the Hund's coupling in these materials.

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Coexistence of excited polarons and metastable delocalized states in photoinduced metals

Cited by 29 publications

References 56 publications

Real-time decay of a highly excited charge carrier in the one-dimensional Holstein model

Real-time decay of a highly excited charge carrier in the one-dimensional Holstein model

Dynamics of screening in photodoped Mott insulators

Hund's coupling driven photocarrier relaxation in the two-band Mott insulator

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