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.
, Lu, M.
, Fritsch, A.
, Reid, G.
and Pineiro Escalera, A.
Floquet engineering topological Dirac bands, Physical Review Letters, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=933761
(Accessed March 30, 2023)