报告题目：Observation of anomalous pi modes in Floquet topological photonics and its application to non-adiabatic elimination

报告人：潘义明博士（Department of Physics of Complex Systems, Weizmann Institute of Science）

主持人：邓伟胤博士

报告时间：2019年5月10日（星期五）下午3:00

报告地点：物理楼（18号楼）二楼213室学术报告厅

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                                     物理与光电学院

                                     2019年5月5日

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内容摘要：Recent progresses on Floquet topological phases have shed new light on time-dependent quantum systems, which exhibit significantly different stroboscopic behaviors from their static counterparts, such as the emergence of anomalous Floquet topological phases (i.e., pi modes) in one-dimensional (1D) Floquet systems. However, to our knowledge so far, experimental observation of these exotic topological modes has never been reported. In this work, by periodically bending ultra-thin metallic microwave arrays of coupled corrugatedwaveguides, we successfully realized a photonic version of the periodically-driven 1D Su-Schrieffer-Heeger model. Through theoretical calculations, numerical simulations and experimental measurements, we observed the Floquet-engineered topological pi modes emerging at certain driving conditions and propagating along the array’s boundary.Especially, the driving conditions of Floquet-engineered topological pi modes are the typical characteristics for ‘topological Floquet engineering’. The dependences of the driving frequencies and the initial input positions (i.e., Floquet gauges) are observed experimentally at the non-adiabatic transition between the extremely slowly-driving limit and infinitely high-frequency limit in our photonic Floquet system, which haven’t been widely noticed for the physics communities yet. Our novelty also lies in the flexible tuning of the driving conditions and highly-integration of the corrugated microwave waveguides fabrications. Therefore, our microwave platform can serve as a powerful ‘Floquet simulator’ for exploring various phenomena related totime-dependent dynamics, such as Thouless charge pumping, non-adiabatic elimination and driven topological phase transitions.

References:

1. Cheng, Q., Optics Express, 26, 31636-31647 (2018); Q. Q. Cheng†, Yiming Pan†*, Huaiqiang Wang†, et al. arXiv:1804.05134 (2018), accepted by PRL, in pressing.

2. Q. Q. Cheng†, Yiming Pan†*, et al. arXiv:1810.00054 (2018), submitted.

3. Rechtsman, M. C., et al. Nature, 496, 196-200 (2013)

4. Ma, H. F., et al.Laser & Photonics Reviews, 8, 146-151 (2014).

5. Eckardt, A., & Anisimovas, E. New journal of physics, 17, 093039. (2015).

6. Cheng, Q., Pan, Y., et al.Laser & Photonics Reviews, 9, 392-398 (2015).

报告人简介：潘义明博士(理论物理PhD)，目前在在以色列威兹曼研究所(2018-目前)和特拉维夫大学(2016-2018)，从事博士后研究工作。潘义明本科毕业于安徽大学应用物理(2010)，硕士博士就读于南京大学凝聚态理论物理专业(2016)，从事二维材料和拓扑绝缘体半金属等材料的量子输运研究。目前，他在以色列博士后工作从事研究的方向有：激光加速器和量子自由电子激光器，光和物质相互作用和冷原子体系中的量子弱测量理论，和Floquet拓扑光子学和量子输运等，主要的合作者有Avraham Gover (Tel Aviv University), Eliahu Cohen (Bar Ilan University), Qingqing Cheng (上海理工大学), Yaron Silberberg和 Nir Davidson (Weizmann Institute of Science)。目前，发表的部分研究工作和成果有：PRL (2篇), Nat. Commu. (1篇), Laser & Photon. Rev (1篇) 和Adv. Mat. (3篇)。更多研究课题和研究兴趣，参看主页: https://www.researchgate.net/profile/Yiming_Pan2.