Anomalous wave-packet transport on boundaries of Floquet topological systems
Fuente:
arXiv
Enregistré dans:
| Auteurs principaux: | , , , |
|---|---|
| Format: | Preprint |
| Publié: |
2024
|
| Sujets: | |
| Accès en ligne: | |
| Tags: |
Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
|
| _version_ | 1866908348341813248 |
|---|---|
| author | Yang, Xin-Xin Shi, Kai-Ye Ünal, F. Nur Zhang, Wei |
| author_facet | Yang, Xin-Xin Shi, Kai-Ye Ünal, F. Nur Zhang, Wei |
| contents | A two-dimensional periodically driven (Floquet) system with zero winding number in the absence of time-reversal symmetry is usually considered topologically trivial. Here, we study the dynamics of a Gaussian wave packet placed at the boundary of a two-dimensional driven system with zero winding numbers but multiple valley-protected edge states that can be realized in a square Raman lattice, and investigate the unidirectionally propagating topological edge currents. By carefully tuning the initial parameters of the wave packet including its spin polarization as well as the initial time of the periodic driving, we control the population of different edge states, where the speed of the resulting propagation establishes a direct correspondence with the target dispersions across different gaps and valleys. Interestingly, we find that the edge states at different valleys in the $π$ gap can hybridize and form bowtie-shaped edge bands fully detached from the bulk. This phase, not only presents a favorable regime with narrower bulk bands, but also exhibits distinct edge dynamics where the majority of particles bounce back-and-forth confined to a boundary while a small portion can follow a chiral transport around the sample. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2412_02086 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | Anomalous wave-packet transport on boundaries of Floquet topological systems Yang, Xin-Xin Shi, Kai-Ye Ünal, F. Nur Zhang, Wei Quantum Gases Mesoscale and Nanoscale Physics Quantum Physics A two-dimensional periodically driven (Floquet) system with zero winding number in the absence of time-reversal symmetry is usually considered topologically trivial. Here, we study the dynamics of a Gaussian wave packet placed at the boundary of a two-dimensional driven system with zero winding numbers but multiple valley-protected edge states that can be realized in a square Raman lattice, and investigate the unidirectionally propagating topological edge currents. By carefully tuning the initial parameters of the wave packet including its spin polarization as well as the initial time of the periodic driving, we control the population of different edge states, where the speed of the resulting propagation establishes a direct correspondence with the target dispersions across different gaps and valleys. Interestingly, we find that the edge states at different valleys in the $π$ gap can hybridize and form bowtie-shaped edge bands fully detached from the bulk. This phase, not only presents a favorable regime with narrower bulk bands, but also exhibits distinct edge dynamics where the majority of particles bounce back-and-forth confined to a boundary while a small portion can follow a chiral transport around the sample. |
| title | Anomalous wave-packet transport on boundaries of Floquet topological systems |
| topic | Quantum Gases Mesoscale and Nanoscale Physics Quantum Physics |
| url | https://arxiv.org/abs/2412.02086 |