Event Details
Speaker Name
Yang-Zhi Chou
Start Date & Time
2021-01-29 12:00 pm
End Date & Time
2021-01-29 12:00 pm
Semester
Event Details

We theoretically study the Hofstadter butterfly of a triangular network model in minimally twisted bilayer graphene. The band structure manifests periodicity in energy, mimicking that of Floquet systems. The butterfly diagrams provide fingerprints of the model parameters and reveal the hidden band topology. In a strong magnetic field, we establish that minimally twisted bilayer graphene realizes low-energy Floquet topological insulators (FTIs) carrying zero Chern number, while hosting chiral edge states in bulk gaps. We identify the FTIs by analyzing the nontrivial spectral flow in the Hofstadter butterfly, and by explicitly computing the chiral edge states. Our theory paves the way for an effective practical realization of FTIs in equilibrium solid-state systems. 

Seminar will be held via Zoom: https://umd.zoom.us/j/97099328991 and Meeting ID : 970 9932 8991 

Misc
Groups
TEMP migration NID
19091