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Title: Photoinduced Hund excitons in the breakdown of a two-orbital Mott insulator

We study the photoinduced breakdown of a two-orbital Mott insulator and resulting metallic state. Using time-dependent density matrix renormalization group, we scrutinize the real-time dynamics of the half-filled two-orbital Hubbard model interacting with a resonant radiation field pulse. The breakdown, caused by production of doublon-holon pairs, is enhanced by Hund's exchange, which dynamically activates large orbital fluctuations. The melting of the Mott insulator is accompanied by a high to low spin transition with a concomitant reduction of antiferromagnetic spin fluctuations. Most notably, the overall time response is driven by the photogeneration of excitons with orbital character that are stabilized by Hund's coupling. These unconventional “Hund excitons” correspond to bound spin-singlet orbital-triplet doublon-holon pairs. We study exciton properties such as bandwidth, binding potential, and size within a semiclassical approach. In conclusion, the photometallic state results from a coexistence of Hund excitons and doublon-holon plasma.
Authors:
 [1] ;  [2] ;  [3]
  1. Perimeter Institute for Theoretical Physics, Waterloo, ON (Canada)
  2. The Univ. of Tennessee, Knoxville, TN (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  3. Northeastern Univ., Boston, MA (United States)
Publication Date:
Grant/Contract Number:
AC05-00OR22725
Type:
Accepted Manuscript
Journal Name:
Physical Review B
Additional Journal Information:
Journal Volume: 97; Journal Issue: 23; Journal ID: ISSN 2469-9950
Publisher:
American Physical Society (APS)
Research Org:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
OSTI Identifier:
1440810

Rincon, Julian, Dagotto, Elbio R., and Feiguin, Adrian E.. Photoinduced Hund excitons in the breakdown of a two-orbital Mott insulator. United States: N. p., Web. doi:10.1103/physrevb.97.235104.
Rincon, Julian, Dagotto, Elbio R., & Feiguin, Adrian E.. Photoinduced Hund excitons in the breakdown of a two-orbital Mott insulator. United States. doi:10.1103/physrevb.97.235104.
Rincon, Julian, Dagotto, Elbio R., and Feiguin, Adrian E.. 2018. "Photoinduced Hund excitons in the breakdown of a two-orbital Mott insulator". United States. doi:10.1103/physrevb.97.235104.
@article{osti_1440810,
title = {Photoinduced Hund excitons in the breakdown of a two-orbital Mott insulator},
author = {Rincon, Julian and Dagotto, Elbio R. and Feiguin, Adrian E.},
abstractNote = {We study the photoinduced breakdown of a two-orbital Mott insulator and resulting metallic state. Using time-dependent density matrix renormalization group, we scrutinize the real-time dynamics of the half-filled two-orbital Hubbard model interacting with a resonant radiation field pulse. The breakdown, caused by production of doublon-holon pairs, is enhanced by Hund's exchange, which dynamically activates large orbital fluctuations. The melting of the Mott insulator is accompanied by a high to low spin transition with a concomitant reduction of antiferromagnetic spin fluctuations. Most notably, the overall time response is driven by the photogeneration of excitons with orbital character that are stabilized by Hund's coupling. These unconventional “Hund excitons” correspond to bound spin-singlet orbital-triplet doublon-holon pairs. We study exciton properties such as bandwidth, binding potential, and size within a semiclassical approach. In conclusion, the photometallic state results from a coexistence of Hund excitons and doublon-holon plasma.},
doi = {10.1103/physrevb.97.235104},
journal = {Physical Review B},
number = 23,
volume = 97,
place = {United States},
year = {2018},
month = {6}
}