Observation of Anomalous π Modes in Photonic Floquet Engineering

Qingqing Cheng*, Yiming Pan, Huaiqiang Wang, Chaoshi Zhang, Dong Yu, Avi Gover, Haijun Zhang, Tao Li, Lei Zhou, Shining Zhu

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Recent progress on Floquet topological phases has shed new light on time-dependant quantum systems, among which one-dimensional (1D) Floquet systems have been under extensive theoretical research. However, an unambiguous experimental observation of these 1D Floquet topological phases is still lacking. Here, by periodically bending an ultrathin metallic array of coupled corrugated waveguides, a photonic Floquet simulator was well designed and successfully fabricated to mimic the periodically driven Su-Schrieffer-Heeger model. Intriguingly, under moderate driven frequencies, we report the first observation of the anomalous Floquet topological π mode, propagating along the array's boundary. The different evolutionary behaviors between static and nonstatic topological end modes have been clearly demonstrated by the microwave near-field experiment. Furthermore, the experiment in the fast-driving regime also reveals the universal high-frequency behavior in driven systems. Our photonic simulator can serve as a versatile testing ground for various phenomena related to time-dependant 1D quantum phases, such as Thouless pumping and dynamical localization.

Original languageEnglish
Article number173901
JournalPhysical Review Letters
Issue number17
StatePublished - 3 May 2019


FundersFunder number
Council for Higher Education
National Key Research and Development Program of China2017YFA0303504, 2017YFA0303701
Science and Technology Commission of Shanghai Municipality16ZR1445600, 16JC1403100
National Key Research and Development Program of China2015CB352001
Fundamental Research Funds for the Central Universities020414380038
Fok Ying Tong Education Foundation161006
United States-Israel Binational Science Foundation00010001000
National Natural Science Foundation of China11734007, 11874266, 11474057, 11621091, 11322439, 11674165, 11604208, 11674068, 11674167


    Dive into the research topics of 'Observation of Anomalous π Modes in Photonic Floquet Engineering'. Together they form a unique fingerprint.

    Cite this