Topological Micromotion of Floquet Quantum Systems
arXiv:2106.14628 · doi:10.1103/PhysRevB.105.045139
Abstract
The Floquet Hamiltonian has often been used to describe a time-periodic system. Nevertheless, because the Floquet Hamiltonian depends on a micro-motion parameter, the Floquet Hamiltonian with a fixed micro-motion parameter cannot faithfully represent a driven system, which manifests as the anomalous edge states. Here we show that an accurate description of a Floquet system requires a set of Hamiltonian exhausting all values of the micro-motion parameter, and this micro-motion parameter can be viewed as an extra synthetic dimension of the system. Therefore, we show that a -dimensional Floquet system can be described by a -dimensional static Hamiltonian, and the advantage of this representation is that the periodic boundary condition is automatically imposed along the extra-dimension, which enables a straightforward definition of topological invariants. The topological invariant in the -dimensional system can ensure a -dimensional edge state of the -dimensional Floquet system. Here we show two examples where the topological invariant is a three-dimensional Hopf invariant. We highlight that our scheme of classifying Floquet topology on the micro-motion space is different from the previous classification of Floquet topology on the time space.
6 pages, 3 figures
References in corpus (15)
- Photovoltaic Hall effect in graphene
- Topological characterization of periodically-driven quantum systems
- Measuring the Chern number of Hofstadter bands with ultracold bosonic atoms
- Periodically-driven quantum systems: Effective Hamiltonians and engineered gauge fields
- Dynamical control of matter-wave tunneling in periodic potentials
- Tunable gauge potential for neutral and spinless particles in driven lattices
- Observation of photon-assisted tunneling in optical lattices
- Observation of a prethermal discrete time crystal
- Topological surface states in three-dimensional magnetic insulators
- Periodically-driven quantum matter: the case of resonant modulations
- Collective emission of matter-wave jets from driven Bose-Einstein condensates
- Collective excitation of a Bose-Einstein condensate by modulation of the atomic scattering length
- Higgs mode in a strongly interacting fermionic superfluid
- Helical Floquet Channels in 1D Lattices
- Time-domain grating with a periodically driven qutrit