Pressure-dependent relaxation in the photoexcited mott insulator ET-F2TCNQ: influence of hopping and correlations on quasiparticle recombination rates.

Journal article

We measure the ultrafast recombination of photoexcited quasiparticles (holon-doublon pairs) in the one dimensional Mott insulator ET-F(2)TCNQ as a function of external pressure, which is used to tune the electronic structure. At each pressure value, we first fit the static optical properties and extract the electronic bandwidth t and the intersite correlation energy V. We then measure the recombination times as a function of pressure, and we correlate them with the corresponding microscopic parameters. We find that the recombination times scale differently than for metals and semiconductors. A fit to our data based on the time-dependent extended Hubbard Hamiltonian suggests that the competition between local recombination and delocalization of the Mott-Hubbard exciton dictates the efficiency of the recombination.

Authors: Mitrano, M; Cotugno, G; Clark, S; Singla, R; Kaiser, S

• Publication status: Published
• Journal: Physical Review Letters
• Volume: 112
• Issue: 11
• Pages: 117801
• Publication date: 2014-03-18
• DOI: 10.1103/physrevlett.112.117801
• EISSN: 1079-7114
• ISSN: 0031-9007
• Language: English
• Keywords: Heterocyclic Compounds; Pressure; Optics and Photonics; Fleroxacin; Nitriles; Models, Chemical