Floquet-Bloch Valleytronics
Fuente:
arXiv
Saved in:
| Main Authors: | , , , , , , , , |
|---|---|
| Format: | Preprint |
| Published: |
2024
|
| Subjects: | |
| Online Access: | |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866916700660695040 |
|---|---|
| author | Fragkos, Sotirios Fabre, Baptiste Tkach, Olena Petit, Stéphane Descamps, Dominique Schönhense, Gerd Mairesse, Yann Schüler, Michael Beaulieu, Samuel |
| author_facet | Fragkos, Sotirios Fabre, Baptiste Tkach, Olena Petit, Stéphane Descamps, Dominique Schönhense, Gerd Mairesse, Yann Schüler, Michael Beaulieu, Samuel |
| contents | Driving quantum materials out-of-equilibrium makes it possible to generate states of matter inaccessible through standard equilibrium tuning methods. Upon time-periodic coherent driving of electrons using electromagnetic fields, the emergence of Floquet-Bloch states enables the creation and control of exotic quantum phases. In transition metal dichalcogenides, broken inversion symmetry within each monolayer results in a non-zero Berry curvature at the K and K$^{\prime}$ valley extrema, giving rise to chiroptical selection rules that are fundamental to valleytronics. Here, we bridge the gap between these two concepts and introduce Floquet-Bloch valleytronics. Using time- and polarization-resolved extreme ultraviolet momentum microscopy combined with state-of-the-art ab initio theory, we demonstrate the formation of valley-polarized Floquet-Bloch states in 2H-WSe$_2$ upon below-bandgap coherent electron driving with chiral light pulses. We investigate quantum path interference between Floquet-Bloch and Volkov states, showing that this interferometric process depends on the valley pseudospin and light polarization-state. Conducting extreme ultraviolet photoemission circular dichroism in these nonequilibrium settings reveals the potential for controlling the orbital character of Floquet-engineered states. These findings link Floquet engineering and quantum geometric light-matter coupling in two-dimensional materials. They can serve as a guideline for reaching novel out-of-equilibrium phases of matter by dynamically breaking symmetries through coherent dressing of winding Bloch electrons with tailored light pulses. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2412_03935 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | Floquet-Bloch Valleytronics Fragkos, Sotirios Fabre, Baptiste Tkach, Olena Petit, Stéphane Descamps, Dominique Schönhense, Gerd Mairesse, Yann Schüler, Michael Beaulieu, Samuel Mesoscale and Nanoscale Physics Driving quantum materials out-of-equilibrium makes it possible to generate states of matter inaccessible through standard equilibrium tuning methods. Upon time-periodic coherent driving of electrons using electromagnetic fields, the emergence of Floquet-Bloch states enables the creation and control of exotic quantum phases. In transition metal dichalcogenides, broken inversion symmetry within each monolayer results in a non-zero Berry curvature at the K and K$^{\prime}$ valley extrema, giving rise to chiroptical selection rules that are fundamental to valleytronics. Here, we bridge the gap between these two concepts and introduce Floquet-Bloch valleytronics. Using time- and polarization-resolved extreme ultraviolet momentum microscopy combined with state-of-the-art ab initio theory, we demonstrate the formation of valley-polarized Floquet-Bloch states in 2H-WSe$_2$ upon below-bandgap coherent electron driving with chiral light pulses. We investigate quantum path interference between Floquet-Bloch and Volkov states, showing that this interferometric process depends on the valley pseudospin and light polarization-state. Conducting extreme ultraviolet photoemission circular dichroism in these nonequilibrium settings reveals the potential for controlling the orbital character of Floquet-engineered states. These findings link Floquet engineering and quantum geometric light-matter coupling in two-dimensional materials. They can serve as a guideline for reaching novel out-of-equilibrium phases of matter by dynamically breaking symmetries through coherent dressing of winding Bloch electrons with tailored light pulses. |
| title | Floquet-Bloch Valleytronics |
| topic | Mesoscale and Nanoscale Physics |
| url | https://arxiv.org/abs/2412.03935 |