Programme

P.90 -- Posters, VCTP-51

Date: Thursday, 6 August 2026

Time: 09:30 - 10:30

Floquet band engineering in graphene from perturbative to extreme driving: a multi-photon driven-Dirac observability map

Dr. Duc-Long Nguyen1,2

1Simulation in Materials Science Research Group, Science and Technology Advanced Institute, Van Lang University, Ho Chi Minh City, Vietnam 2Faculty of Applied Technology, School of Technology, Van Lang University, Ho Chi Minh City, Vietnam

Floquet engineering is a method of controlling the dynamic electronic structure of quantum mat- ter, the regime of which has been experimentally verified in graphene, although mostly to small driving. We consider in this paper single-layer graphene, which is pumped with high-order multi- photon driven Dirac Floquet strong linearly and circularly polarized mid-infrared light. The gap between the one-photon hybridization is reappeared in the perturbative regime and its development is continued into the nonperturbative limit. Here the higher-order n =2 and n=3 Floquet signals, sharp spectralweight redistribution, and nonmonotonic strong-field gap renormalization can be found. We demonstrate that the nodal direction which is symmetry-protected remains strong in all resolved photon sectors in the driven-Dirac model when the driving is linearly polarized. We obtain a gap induced by light which is identical at the Dirac point on both sides in circular polarization which is consistent with a Haldane-like Floquet mass term. To quantify observability, we apply phenomeno- logical widening and chart the range of linewidths over which higher-order Floquet effects can be spectroscopically resolved. We find a model phase diagram of the onset of strong-field Floquet behavior in graphene. They also indicate the signals that are strong, those that are restricted by coherence and those that require more models detailed to be compared directly in the laboratory.

Presenter: Nguyen Duc Long