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Floquet engineering topological Dirac bands



Ian Spielman, Mingwu Lu, Amilson R. Fritsch, Graham Reid, Alina Pineiro Escalera


We experimentally realized a time-periodically modulated 1D lattice for ultracold atoms featuring a pair of linear bands, each associated with a Floquet winding number: a topological invariant. These bands are spin-momentum locked and almost perfectly linear everywhere in the Brillouin zone (BZ), making this system a near-ideal realization of the 1D Dirac Hamiltonian. We characterized the Floquet winding number using a form of quantum state tomography, covering the BZ and following the micromotion through one Floquet period. Lastly, we altered the modulation timing to lift the topological protection, opening a gap at the Dirac point that grew in proportion to the deviation from the topological configuration.
Physical Review Letters


Bose Einstein Condensate, Floquet, Dirac


Spielman, I. , Lu, M. , Fritsch, A. , Reid, G. and Pineiro Escalera, A. (2022), Floquet engineering topological Dirac bands, Physical Review Letters, [online], (Accessed April 14, 2024)
Created July 22, 2022, Updated November 29, 2022