Resonant Excitation of the Ferroelectric Soft Mode by a Narrow-Band THz Pulse
This study investigates the impact of narrow-band terahertz pulses on the ferroelectric order parameter in Ba<sub>0.8</sub>Sr<sub>0.2</sub>TiO<sub>3</sub> films on various substrates. THz radiation in the range of 1–2 THz with the pulse width of about 0.15 THz was...
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MDPI AG
2023-06-01
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| Series: | Nanomaterials |
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| Online Access: | https://www.mdpi.com/2079-4991/13/13/1961 |
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| author | Kirill Brekhov Vladislav Bilyk Andrey Ovchinnikov Oleg Chefonov Vladimir Mukhortov Elena Mishina |
| author_facet | Kirill Brekhov Vladislav Bilyk Andrey Ovchinnikov Oleg Chefonov Vladimir Mukhortov Elena Mishina |
| author_sort | Kirill Brekhov |
| collection | DOAJ |
| description | This study investigates the impact of narrow-band terahertz pulses on the ferroelectric order parameter in Ba<sub>0.8</sub>Sr<sub>0.2</sub>TiO<sub>3</sub> films on various substrates. THz radiation in the range of 1–2 THz with the pulse width of about 0.15 THz was separated from a broadband pulse with the interference technique. The 375 nm thick BST film on a MgO (001) substrate exhibits enhanced THz-induced second harmonic generation when excited by THz pulses with a central frequency of 1.6 THz, due to the resonant excitation of the soft phonon mode. Conversely, the BST film on a Si (001) substrate shows no enhancement, due to its polycrystalline state. The 800 nm thick BST film on a MgO (111) substrate demonstrates the maximum of a second harmonic generation signal when excited by THz pulses at 1.8 THz, which is close to the soft mode frequency for the (111) orientation. Notably, the frequency spectrum of the BST/MgO (111) film reveals peaks at both the fundamental and doubled frequencies, and their intensities depend, respectively, linearly and quadratically on the THz pulse electric field strength. |
| first_indexed | 2024-03-11T01:33:03Z |
| format | Article |
| id | doaj.art-3096b6e2398e485ca8666a13e450c3f0 |
| institution | Directory Open Access Journal |
| issn | 2079-4991 |
| language | English |
| last_indexed | 2024-03-11T01:33:03Z |
| publishDate | 2023-06-01 |
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| series | Nanomaterials |
| spelling | doaj.art-3096b6e2398e485ca8666a13e450c3f02023-11-18T17:11:56ZengMDPI AGNanomaterials2079-49912023-06-011313196110.3390/nano13131961Resonant Excitation of the Ferroelectric Soft Mode by a Narrow-Band THz PulseKirill Brekhov0Vladislav Bilyk1Andrey Ovchinnikov2Oleg Chefonov3Vladimir Mukhortov4Elena Mishina5Department of Nanoelectronics, MIREA—Russian Technological University, Moscow 119454, RussiaInstitute for Molecules and Materials, Radboud University, 6525 AJ Nijmegen, The NetherlandsJoint Institute for High Temperatures of Russian Academy of Sciences (JIHT), Moscow 125412, RussiaJoint Institute for High Temperatures of Russian Academy of Sciences (JIHT), Moscow 125412, RussiaSouthern Scientific Center of Russian Academy of Sciences, Rostov-on-Don 344006, RussiaDepartment of Nanoelectronics, MIREA—Russian Technological University, Moscow 119454, RussiaThis study investigates the impact of narrow-band terahertz pulses on the ferroelectric order parameter in Ba<sub>0.8</sub>Sr<sub>0.2</sub>TiO<sub>3</sub> films on various substrates. THz radiation in the range of 1–2 THz with the pulse width of about 0.15 THz was separated from a broadband pulse with the interference technique. The 375 nm thick BST film on a MgO (001) substrate exhibits enhanced THz-induced second harmonic generation when excited by THz pulses with a central frequency of 1.6 THz, due to the resonant excitation of the soft phonon mode. Conversely, the BST film on a Si (001) substrate shows no enhancement, due to its polycrystalline state. The 800 nm thick BST film on a MgO (111) substrate demonstrates the maximum of a second harmonic generation signal when excited by THz pulses at 1.8 THz, which is close to the soft mode frequency for the (111) orientation. Notably, the frequency spectrum of the BST/MgO (111) film reveals peaks at both the fundamental and doubled frequencies, and their intensities depend, respectively, linearly and quadratically on the THz pulse electric field strength.https://www.mdpi.com/2079-4991/13/13/1961THz excitationferroelectricsecond harmonic generation |
| spellingShingle | Kirill Brekhov Vladislav Bilyk Andrey Ovchinnikov Oleg Chefonov Vladimir Mukhortov Elena Mishina Resonant Excitation of the Ferroelectric Soft Mode by a Narrow-Band THz Pulse Nanomaterials THz excitation ferroelectric second harmonic generation |
| title | Resonant Excitation of the Ferroelectric Soft Mode by a Narrow-Band THz Pulse |
| title_full | Resonant Excitation of the Ferroelectric Soft Mode by a Narrow-Band THz Pulse |
| title_fullStr | Resonant Excitation of the Ferroelectric Soft Mode by a Narrow-Band THz Pulse |
| title_full_unstemmed | Resonant Excitation of the Ferroelectric Soft Mode by a Narrow-Band THz Pulse |
| title_short | Resonant Excitation of the Ferroelectric Soft Mode by a Narrow-Band THz Pulse |
| title_sort | resonant excitation of the ferroelectric soft mode by a narrow band thz pulse |
| topic | THz excitation ferroelectric second harmonic generation |
| url | https://www.mdpi.com/2079-4991/13/13/1961 |
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