Theory of time-crystalline behaviour mediated by phonon squeezing in Ta2NiSe5
Fuente:
arXiv
Saved in:
| Main Authors: | , , , , , , , |
|---|---|
| Format: | Preprint |
| Published: |
2022
|
| Subjects: | |
| Online Access: | |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866914950252855296 |
|---|---|
| author | Michael, Marios H. Haque, Sheikh Rubaiat Ul Windgaetter, Lukas Latini, Simone Zhang, Yuan Rubio, Angel Averitt, Richard D. Demler, Eugene |
| author_facet | Michael, Marios H. Haque, Sheikh Rubaiat Ul Windgaetter, Lukas Latini, Simone Zhang, Yuan Rubio, Angel Averitt, Richard D. Demler, Eugene |
| contents | We theoretically investigate photonic time-crystalline behaviour initiated by optical excitation above the electronic gap of the excitonic insulator candidate $\rm{Ta_2 Ni Se_5}$. We show that after electron photoexcitation, electron-phonon coupling leads to an unconventional squeezed phonon state, characterised by periodic oscillations of phonon fluctuations. Squeezing oscillations lead to photonic time crystalline behaviour. The key signature of the photonic time crystalline behaviour is THz amplification of reflectivity in a narrow frequency band. The theory is supported by experimental results on $\rm{Ta_2 Ni Se_5}$ where photoexcitation with short pulses leads to enhanced terahertz reflectivity with the predicted features. We explain the key mechanism leading to THz amplification in terms of a simplified Hamiltonian whose validity is supported by ab-initio DFT calculations. Our theory suggests that the pumped $\rm{Ta_2 Ni Se_5}$ is a gain medium, demonstrating that squeezed phonon noise may be used to create THz amplifiers in THz communication applications. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2207_08851 |
| institution | arXiv |
| publishDate | 2022 |
| record_format | arxiv |
| spellingShingle | Theory of time-crystalline behaviour mediated by phonon squeezing in Ta2NiSe5 Michael, Marios H. Haque, Sheikh Rubaiat Ul Windgaetter, Lukas Latini, Simone Zhang, Yuan Rubio, Angel Averitt, Richard D. Demler, Eugene Strongly Correlated Electrons Quantum Physics We theoretically investigate photonic time-crystalline behaviour initiated by optical excitation above the electronic gap of the excitonic insulator candidate $\rm{Ta_2 Ni Se_5}$. We show that after electron photoexcitation, electron-phonon coupling leads to an unconventional squeezed phonon state, characterised by periodic oscillations of phonon fluctuations. Squeezing oscillations lead to photonic time crystalline behaviour. The key signature of the photonic time crystalline behaviour is THz amplification of reflectivity in a narrow frequency band. The theory is supported by experimental results on $\rm{Ta_2 Ni Se_5}$ where photoexcitation with short pulses leads to enhanced terahertz reflectivity with the predicted features. We explain the key mechanism leading to THz amplification in terms of a simplified Hamiltonian whose validity is supported by ab-initio DFT calculations. Our theory suggests that the pumped $\rm{Ta_2 Ni Se_5}$ is a gain medium, demonstrating that squeezed phonon noise may be used to create THz amplifiers in THz communication applications. |
| title | Theory of time-crystalline behaviour mediated by phonon squeezing in Ta2NiSe5 |
| topic | Strongly Correlated Electrons Quantum Physics |
| url | https://arxiv.org/abs/2207.08851 |