Saved in:
| Main Authors: | , , , , , , , , , , , , , , , , , , , , , , , , , |
|---|---|
| Format: | Preprint |
| Published: |
2025
|
| Subjects: | |
| Online Access: | https://arxiv.org/abs/2509.16493 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866908549130485760 |
|---|---|
| author | Oh, Kyoung Hun Su, Yifan Ning, Honglie Lv, B. Q. Zong, Alfred Wu, Dong Liu, Qiaomei Kang, Gyeongbo Choi, Hyeongi Kim, Hyun-Woo J. Ha, Seunghyeok Kim, Jaehwon Sarker, Suchismita Ruff, Jacob P. C. Shen, Xiaozhe Luo, Duan Weathersby, Stephen Kramer, Patrick Cheng, Xinxin Choi, Dongsung Azoury, Doron Mogi, Masataka Kim, B. J. Wang, N. L. Jang, Hoyoung Gedik, Nuh |
| author_facet | Oh, Kyoung Hun Su, Yifan Ning, Honglie Lv, B. Q. Zong, Alfred Wu, Dong Liu, Qiaomei Kang, Gyeongbo Choi, Hyeongi Kim, Hyun-Woo J. Ha, Seunghyeok Kim, Jaehwon Sarker, Suchismita Ruff, Jacob P. C. Shen, Xiaozhe Luo, Duan Weathersby, Stephen Kramer, Patrick Cheng, Xinxin Choi, Dongsung Azoury, Doron Mogi, Masataka Kim, B. J. Wang, N. L. Jang, Hoyoung Gedik, Nuh |
| contents | The advent of two-dimensional moiré systems has revolutionized the exploration of phenomena arising from strong correlations and nontrivial band topology. Recently, a moiré superstructure formed by two coexisting charge density wave (CDW) orders with slightly mismatched wavevectors has been realized. These incommensurate CDWs can collectively exhibit commensurability, resulting in the jointly commensurate CDW (JC-CDW). This JC-CDW hosts phenomena including electronic anisotropy and phase-modulated hysteresis, and holds promise for non-volatile optoelectronic memory devices. Realizing such functionality requires understanding how the spatial periodicity, coherence, and amplitude of this order evolve under perturbations. Here, we address these questions using time- and momentum-resolved techniques to probe light-induced dynamics in EuTe$_4$. Our time-resolved diffraction results show that under intense photoexcitation, the JC-CDW wavevector and coherence length remain locked along the CDW direction, indicating preserved moiré periodicity while the moiré potential depth is suppressed. This robustness governs the configuration of the photoexcited JC-CDW and leads to the formation of previously underexplored shear-type topological defects. Furthermore, we developed an approach to simultaneously track the temporal evolution of the amplitude and phase of a CDW by following two diffraction peaks corresponding to one order, with findings verified by time-resolved photoemission and electron diffraction. This methodology enables reconstruction of the momentum- and time-resolved evolution of the JC-CDW and direct visualization of shear-type topological defect formation. These findings not only highlight the unique robustness of JC-CDWs out of equilibrium, but also establish a platform for optical moiré engineering and manipulation of quantum materials through topological defect control. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2509_16493 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Joint commensuration in moiré charge-order superlattices drives shear topological defects Oh, Kyoung Hun Su, Yifan Ning, Honglie Lv, B. Q. Zong, Alfred Wu, Dong Liu, Qiaomei Kang, Gyeongbo Choi, Hyeongi Kim, Hyun-Woo J. Ha, Seunghyeok Kim, Jaehwon Sarker, Suchismita Ruff, Jacob P. C. Shen, Xiaozhe Luo, Duan Weathersby, Stephen Kramer, Patrick Cheng, Xinxin Choi, Dongsung Azoury, Doron Mogi, Masataka Kim, B. J. Wang, N. L. Jang, Hoyoung Gedik, Nuh Strongly Correlated Electrons Materials Science The advent of two-dimensional moiré systems has revolutionized the exploration of phenomena arising from strong correlations and nontrivial band topology. Recently, a moiré superstructure formed by two coexisting charge density wave (CDW) orders with slightly mismatched wavevectors has been realized. These incommensurate CDWs can collectively exhibit commensurability, resulting in the jointly commensurate CDW (JC-CDW). This JC-CDW hosts phenomena including electronic anisotropy and phase-modulated hysteresis, and holds promise for non-volatile optoelectronic memory devices. Realizing such functionality requires understanding how the spatial periodicity, coherence, and amplitude of this order evolve under perturbations. Here, we address these questions using time- and momentum-resolved techniques to probe light-induced dynamics in EuTe$_4$. Our time-resolved diffraction results show that under intense photoexcitation, the JC-CDW wavevector and coherence length remain locked along the CDW direction, indicating preserved moiré periodicity while the moiré potential depth is suppressed. This robustness governs the configuration of the photoexcited JC-CDW and leads to the formation of previously underexplored shear-type topological defects. Furthermore, we developed an approach to simultaneously track the temporal evolution of the amplitude and phase of a CDW by following two diffraction peaks corresponding to one order, with findings verified by time-resolved photoemission and electron diffraction. This methodology enables reconstruction of the momentum- and time-resolved evolution of the JC-CDW and direct visualization of shear-type topological defect formation. These findings not only highlight the unique robustness of JC-CDWs out of equilibrium, but also establish a platform for optical moiré engineering and manipulation of quantum materials through topological defect control. |
| title | Joint commensuration in moiré charge-order superlattices drives shear topological defects |
| topic | Strongly Correlated Electrons Materials Science |
| url | https://arxiv.org/abs/2509.16493 |