We investigate the possibility of realizing a disorder-induced topological Floquet spectrum in two-dimensional periodically driven systems. Such a state would be a dynamical realization of the topological Anderson insulator. We establish that a disorder-induced trivial-to-topological transition indeed occurs, and characterize it by computing the disorder averaged Bott index, suitably defined for the time-dependent system. The presence of edge states in the topological state is confirmed by exact numerical time evolution of wave packets on the edge of the system. We consider the optimal driving regime for experimentally observing the Floquet topological Anderson insulator, and discuss its possible realization in photonic lattices.
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http://dx.doi.org/10.1103/PhysRevLett.114.056801 | DOI Listing |
Phys Rev Lett
December 2024
Institute for Structure and Function and Department of Physics and Chongqing Key Laboratory for Strongly Coupled Physics, Chongqing University, Chongqing 400044, People's Republic of China and Center of Quantum Materials and Devices, Chongqing University, Chongqing 400044, People's Republic of China.
Recent studies have attracted widespread attention on magnet-superconductor hybrid systems with emergent topological superconductivity. Here, we present the Floquet engineering of realistic two-dimensional topological nodal-point superconductors that are composed of antiferromagnetic monolayers in proximity to an s-wave superconductor. We show that Floquet chiral topological superconductivity arises due to light-induced breaking of the effective time-reversal symmetry.
View Article and Find Full Text PDFNat Commun
January 2025
Institute of Physics, Chinese Academy of Sciences, Beijing, China.
Topological phases are robust against weak perturbations, but break down when disorder becomes sufficiently strong. However, moderate disorder can also induce topologically nontrivial phases. Thouless pumping, as a (1+1)D counterpart of the integer quantum Hall effect, is one of the simplest manifestations of topology.
View Article and Find Full Text PDFNat Commun
December 2024
Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, MD, USA.
Non-Hermitian models describe the physics of ubiquitous open systems with gain and loss. One intriguing aspect of non-Hermitian models is their inherent topology that can produce intriguing boundary phenomena like resilient higher-order topological insulators (HOTIs) and non-Hermitian skin effects (NHSE). Recently, time-multiplexed lattices in synthetic dimensions have emerged as a versatile platform for the investigation of these effects free of geometric restrictions.
View Article and Find Full Text PDFNanophotonics
November 2024
College of Science, China University of Petroleum (East China), Qingdao 266580, China.
Owing to its topological properties and band collapse, Floquet helical photonic lattices have gained increasing attention as a purely classical setting to realize the optical analogues of a wide variety of quantum phenomena. We demonstrate both theoretically and numerically that light propagation in an appropriately designed helical superlattice can exhibit spatial photonic Zitterbewegung effect, i.e.
View Article and Find Full Text PDFJ Phys Condens Matter
December 2024
Department of Physics, University of Allahabad, Prayagraj 211002, India.
The irradiation of topological insulator surface with elliptically polarized light modifies the topological properties in a phase-dependent manner impacting the Floquet Chern number which is a crucial topological invariant associated with such driven systems. Employing Floquet theory in presence of hexagonal warping term in the Dirac fermion Hamiltonian under off-resonant conditions, we derive an effective Hamiltonian that highlights distinct features in the Floquet-Dirac surface states. Specifically, we identify a helicity and ellipticity-dependent mass term in the quasi-static Hamiltonian, breaking time reversal symmetry.
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