Dynamical aspects of excitonic Floquet states generated by a phase-locked mid-infrared pulse in a one-dimensional Mott insulator
A periodic electric field of light applied on a solid is predicted to generate coupled states of the light electric fields and electronic system called photon-dressed Floquet states. Previous studies of those Floquet states have focused on time-averaged energy-level structures. Here, we report time-...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2023-01-01
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| Series: | New Journal of Physics |
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| Online Access: | https://doi.org/10.1088/1367-2630/acf72a |
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| author | Takashi Yamakawa Tatsuya Miyamoto Daiki Sakai Hiroshi Okamoto |
| author_facet | Takashi Yamakawa Tatsuya Miyamoto Daiki Sakai Hiroshi Okamoto |
| author_sort | Takashi Yamakawa |
| collection | DOAJ |
| description | A periodic electric field of light applied on a solid is predicted to generate coupled states of the light electric fields and electronic system called photon-dressed Floquet states. Previous studies of those Floquet states have focused on time-averaged energy-level structures. Here, we report time-dependent responses of Floquet states of excitons generated by a mid-infrared (MIR) pulse excitation in a prototypical one-dimensional (1D) Mott insulator, a chlorine-bridged nickel-chain compound, [Ni(chxn) _2 Cl](NO _3 ) _2 (chxn = cyclohexanediamine). Sub-cycle reflection spectroscopy on this compound using a phase-locked MIR pump pulse and an ultrashort visible probe pulse with the temporal width of ∼7 fs revealed that large and ultrafast reflectivity changes occur along the electric field of the MIR pulse; the reflectivity change reached approximately 50% of the original value around the exciton absorption peak. It comprised a high-frequency oscillation at twice the frequency of the MIR pulse and a low-frequency component following the intensity envelope of the MIR pulse, which showed different probe-energy dependences. Simulations considering one-photon-allowed and one-photon-forbidden excitons reproduced the temporal and spectral characteristics of both the high-frequency oscillation and low-frequency component. These simulations demonstrated that all responses originated from the quantum interferences of the linear reflection process and nonlinear light-scattering processes owing to the excitonic Floquet states characteristic of 1D Mott insulators. The present results lead to the developments of Floquet engineering, and demonstrate the possibility of rapidly controlling the intensity of visible or near-IR pulse by varying the phase of MIR electric fields, which will be utilized for ultrafast optical switching devices. |
| first_indexed | 2024-03-11T22:04:42Z |
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| id | doaj.art-44a75551a8184ea1bb04f0e7eb319457 |
| institution | Directory Open Access Journal |
| issn | 1367-2630 |
| language | English |
| last_indexed | 2024-03-11T22:04:42Z |
| publishDate | 2023-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | New Journal of Physics |
| spelling | doaj.art-44a75551a8184ea1bb04f0e7eb3194572023-09-25T09:19:04ZengIOP PublishingNew Journal of Physics1367-26302023-01-0125909304410.1088/1367-2630/acf72aDynamical aspects of excitonic Floquet states generated by a phase-locked mid-infrared pulse in a one-dimensional Mott insulatorTakashi Yamakawa0https://orcid.org/0000-0002-7451-5918Tatsuya Miyamoto1https://orcid.org/0000-0001-7571-1964Daiki Sakai2Hiroshi Okamoto3https://orcid.org/0000-0003-2807-5277Department of Advanced Materials Science, University of Tokyo , Chiba 277-8561, JapanDepartment of Advanced Materials Science, University of Tokyo , Chiba 277-8561, JapanDepartment of Advanced Materials Science, University of Tokyo , Chiba 277-8561, JapanDepartment of Advanced Materials Science, University of Tokyo , Chiba 277-8561, JapanA periodic electric field of light applied on a solid is predicted to generate coupled states of the light electric fields and electronic system called photon-dressed Floquet states. Previous studies of those Floquet states have focused on time-averaged energy-level structures. Here, we report time-dependent responses of Floquet states of excitons generated by a mid-infrared (MIR) pulse excitation in a prototypical one-dimensional (1D) Mott insulator, a chlorine-bridged nickel-chain compound, [Ni(chxn) _2 Cl](NO _3 ) _2 (chxn = cyclohexanediamine). Sub-cycle reflection spectroscopy on this compound using a phase-locked MIR pump pulse and an ultrashort visible probe pulse with the temporal width of ∼7 fs revealed that large and ultrafast reflectivity changes occur along the electric field of the MIR pulse; the reflectivity change reached approximately 50% of the original value around the exciton absorption peak. It comprised a high-frequency oscillation at twice the frequency of the MIR pulse and a low-frequency component following the intensity envelope of the MIR pulse, which showed different probe-energy dependences. Simulations considering one-photon-allowed and one-photon-forbidden excitons reproduced the temporal and spectral characteristics of both the high-frequency oscillation and low-frequency component. These simulations demonstrated that all responses originated from the quantum interferences of the linear reflection process and nonlinear light-scattering processes owing to the excitonic Floquet states characteristic of 1D Mott insulators. The present results lead to the developments of Floquet engineering, and demonstrate the possibility of rapidly controlling the intensity of visible or near-IR pulse by varying the phase of MIR electric fields, which will be utilized for ultrafast optical switching devices.https://doi.org/10.1088/1367-2630/acf72aMott insulatorFloquet statemid-infrared pulsenonlinear opticsultrafast spectroscopy |
| spellingShingle | Takashi Yamakawa Tatsuya Miyamoto Daiki Sakai Hiroshi Okamoto Dynamical aspects of excitonic Floquet states generated by a phase-locked mid-infrared pulse in a one-dimensional Mott insulator New Journal of Physics Mott insulator Floquet state mid-infrared pulse nonlinear optics ultrafast spectroscopy |
| title | Dynamical aspects of excitonic Floquet states generated by a phase-locked mid-infrared pulse in a one-dimensional Mott insulator |
| title_full | Dynamical aspects of excitonic Floquet states generated by a phase-locked mid-infrared pulse in a one-dimensional Mott insulator |
| title_fullStr | Dynamical aspects of excitonic Floquet states generated by a phase-locked mid-infrared pulse in a one-dimensional Mott insulator |
| title_full_unstemmed | Dynamical aspects of excitonic Floquet states generated by a phase-locked mid-infrared pulse in a one-dimensional Mott insulator |
| title_short | Dynamical aspects of excitonic Floquet states generated by a phase-locked mid-infrared pulse in a one-dimensional Mott insulator |
| title_sort | dynamical aspects of excitonic floquet states generated by a phase locked mid infrared pulse in a one dimensional mott insulator |
| topic | Mott insulator Floquet state mid-infrared pulse nonlinear optics ultrafast spectroscopy |
| url | https://doi.org/10.1088/1367-2630/acf72a |
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