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

Abstract

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:
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)
OSTI Identifier:
1440810
Grant/Contract Number:  
AC05-00OR22725
Resource Type:
Journal Article: 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)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS

Citation Formats

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., 2018. 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. Tue . "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 = {Tue Jun 05 00:00:00 EDT 2018},
month = {Tue Jun 05 00:00:00 EDT 2018}
}

Journal Article:
Free Publicly Available Full Text
This content will become publicly available on June 5, 2019
Publisher's Version of Record

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Cited by: 1 work
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