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Reinhoffer C, Esser S, Esser S, Mashkovich EA, Germanskiy S, Gegenwart P, Anders F, van Loosdrecht PHM, Wang Z. Strong Terahertz Third-Harmonic Generation by Kinetic Heavy Quasiparticles in CaRuO_{3}. PHYSICAL REVIEW LETTERS 2024; 132:196501. [PMID: 38804953 DOI: 10.1103/physrevlett.132.196501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2023] [Accepted: 04/15/2024] [Indexed: 05/29/2024]
Abstract
We report on time-resolved nonlinear terahertz spectroscopy of a strongly correlated ruthenate, CaRuO_{3}, as a function of temperature, frequency, and terahertz field strength. Third-harmonic radiation for frequencies up to 2.1 THz is observed evidently at low temperatures below 80 K, where the low-frequency linear dynamical response deviates from the Drude model and a coherent heavy quasiparticle band emerges by strong correlations associated with the Hund's coupling. Phenomenologically, by taking an experimentally observed frequency-dependent scattering rate, the deviation of the field driven kinetics from the Drude behavior is reconciled in a time-dependent Boltzmann description, which allows an attribution of the observed third-harmonic generation to the terahertz field driven nonlinear kinetics of the heavy quasiparticles.
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Affiliation(s)
- Chris Reinhoffer
- Institute of Physics II, University of Cologne, 50937 Cologne, Germany
| | - Sven Esser
- Experimental Physics VI, Center for Electronic Correlations and Magnetism, University of Augsburg, 86159 Augsburg, Germany
| | - Sebastian Esser
- Experimental Physics VI, Center for Electronic Correlations and Magnetism, University of Augsburg, 86159 Augsburg, Germany
| | | | - Semyon Germanskiy
- Institute of Physics II, University of Cologne, 50937 Cologne, Germany
| | - Philipp Gegenwart
- Experimental Physics VI, Center for Electronic Correlations and Magnetism, University of Augsburg, 86159 Augsburg, Germany
| | - Frithjof Anders
- Department of Physics, TU Dortmund University, 44227 Dortmund, Germany
| | | | - Zhe Wang
- Institute of Physics II, University of Cologne, 50937 Cologne, Germany
- Department of Physics, TU Dortmund University, 44227 Dortmund, Germany
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Galler A, Rubio A, Neufeld O. Mapping Light-Dressed Floquet Bands by Highly Nonlinear Optical Excitations and Valley Polarization. J Phys Chem Lett 2023; 14:11298-11304. [PMID: 38063672 PMCID: PMC10749462 DOI: 10.1021/acs.jpclett.3c02936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Revised: 12/01/2023] [Accepted: 12/04/2023] [Indexed: 12/22/2023]
Abstract
Ultrafast nonlinear optical phenomena in solids have been attracting a great deal of interest as novel methodologies for the femtosecond spectroscopy of electron dynamics and control of the properties of materials. Here, we theoretically investigate strong-field nonlinear optical transitions in a prototypical two-dimensional material, hBN, and show that the k-resolved conduction band charge occupation patterns induced by an elliptically polarized laser can be understood in a multiphoton resonant picture, but, remarkably, only if using the Floquet light-dressed states instead of the undressed matter states. Our work demonstrates that Floquet dressing affects ultrafast charge dynamics and photoexcitation even from a single pump pulse and establishes a direct measurable signature for band dressing in nonlinear optical processes in solids, opening new paths for ultrafast spectroscopy and valley manipulation.
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Affiliation(s)
- Anna Galler
- Max
Planck Institute for the Structure and Dynamics of Matter, Center for Free Electron Laser Science, 22761 Hamburg, Germany
| | - Angel Rubio
- Max
Planck Institute for the Structure and Dynamics of Matter, Center for Free Electron Laser Science, 22761 Hamburg, Germany
- Center
for Computational Quantum Physics, Flatiron
Institute, New York, New York 10010, United States
| | - Ofer Neufeld
- Max
Planck Institute for the Structure and Dynamics of Matter, Center for Free Electron Laser Science, 22761 Hamburg, Germany
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