Dynamical characterization of Weyl nodes in Floquet Weyl semimetal phases

Abstract

Due to studies in nonequilibrium (periodically-driven) topological matter, it is now understood that some topological invariants used to classify equilibrium states of matter do not suffice to describe their nonequilibrium counterparts. Indeed, in Floquet systems the additional gap arising from the periodicity of the quasienergy Brillouin zone often leads to unique topological phenomena without equilibrium analogues. In the context of Floquet Weyl semimetal, Weyl points may be induced at both quasienergy zero and $\pi /T$ ($T$ being the driving period) and these two types of Weyl points can be very close to each other in the momentum space. Because of their momentum-space proximity, the chirality of each individual Weyl point may become hard to characterize in both theory and experiments, thus making it challenging to determine the system's overall topology. In this work, inspired by the construction of dynamical winding numbers in Floquet Chern insulators, we propose a dynamical invariant capable of characterizing and distinguishing between Weyl points at different quasienergy values, thus advancing one step further in the topological characterization of Floquet Weyl semimetals. To demonstrate the usefulness of such a dynamical topological invariant, we consider a variant of the periodically kicked Harper model (the very first model in studies of Floquet topological phases) that exhibits many Weyl points, with the number of Weyl points rising unlimitedly with the strength of some system parameters. Furthermore, we investigate the two-terminal transport signature associated with the Weyl points. Theoretical findings of this work pave the way for experimentally probing the rich topological band structures of some seemingly simple Floquet semimetal systems.

arXiv comment15 pages, 7 figures, this version to appear in Phys. Rev. B

References in corpus (67)

• Topological Insulators
• Topological insulators and superconductors
• Quantum Spin Hall Effect in Graphene
• Quantum Spin Hall Effect and Topological Phase Transition in HgTe Quantum Wells
• Electronic Structure of Pyrochlore Iridates: From Topological Dirac Metal to Mott Insulator
• Topological Insulators in Three Dimensions
• Topological Insulators with Inversion Symmetry
• Discovery (theoretical prediction and experimental observation) of a large-gap topological-insulator class with spin-polarized single-Dirac-cone on the surface
• A topological Dirac insulator in a quantum spin Hall phase : Experimental observation of first strong topological insulator
• Photonic Floquet Topological Insulators
• Discovery of a Weyl Fermion Semimetal and Topological Fermi Arcs
• Topological invariants of time-reversal-invariant band structures
• Weyl Semimetal in a Topological Insulator Multilayer
• Floquet Topological Insulator in Semiconductor Quantum Wells
• Experimental discovery of Weyl semimetal TaAs
• Topological nodal semimetals
• Theoretical Discovery/Prediction: Weyl Semimetal states in the TaAs material (TaAs, NbAs, NbP, TaP) class
• Chern semi-metal and Quantized Anomalous Hall Effect in HgCr2Se4
• Weyl semimetal phase in non-centrosymmetric transition metal monophosphides
• Observation of Floquet-Bloch states on the surface of a topological insulator
• Topological characterization of periodically-driven quantum systems
• Observation of Weyl nodes in TaAs
• Three dimensional topological invariants for time reversal invariant Hamiltonians and the three dimensional quantum spin Hall effect
• Discovery of a Weyl Fermion semimetal state in NbAs
• Topological response in Weyl semimetals and the chiral anomaly
• Light-induced anomalous Hall effect in graphene
• Topological Nodal Line Semimetal and Dirac Semimetal State in Antiperovskite Cu${}_3$PdN
• Majorana Fermions in Equilibrium and Driven Cold Atom Quantum Wires
• Recent developments in transport phenomena in Weyl semimetals
• Dirac Fermions in Solids - from High Tc cuprates and Graphene to Topological Insulators and Weyl Semimetals
• Quantum Oscillations from Surface Fermi-Arcs in Weyl and Dirac Semi-Metals
• Experimental discovery of a topological Weyl semimetal state in TaP
• Creating stable Floquet-Weyl semimetals by laser-driving of 3D Dirac materials
• Spin-orbit-free Weyl-loop and Weyl-point semimetals in a stable three-dimensional carbon allotrope
• Drumhead Surface States and Topological Nodal-Line Fermions in TlTaSe2
• Chiral gauge field and axial anomaly in a Weyl semi-metal
• Realization of an anomalous Floquet topological system with ultracold atoms
• Topological singularities and the general classification of Floquet-Bloch systems
• Line of Dirac Nodes in Hyper-Honeycomb Lattices
• Chiral Anomaly and Diffusive Magnetotransport in Weyl Metals
• Chiral symmetry and bulk--boundary correspondence in periodically driven one-dimensional systems
• Transport signatures of Floquet Majorana fermions in driven topological superconductors
• Topological invariants of Floquet systems: General formulation, special properties, and Floquet topological defects
• Generating Many Majorana Modes via Periodic Driving: A Superconductor Model
• Friedel oscillations due to Fermi arcs in Weyl semimetals
• Quantized Adiabatic Transport in Momentum Space
• Simulation of non-Abelian braiding in Majorana time crystals
• Counter-propagating edge modes and topological phases of a kicked quantum Hall system
• Topological Effects in Chiral Symmetric Driven Systems
• Towards large-Chern-number topological phases by periodic quenching
• Realistic Floquet semimetal with exotic topological linkages between arbitrarily many nodal loops
• Floquet topological semimetal phases of an extended kicked Harper model
• Scattering matrix invariants of Floquet topological insulators
• Recipe for creating an arbitrary number of Floquet chiral edge states
• Quantum computation via Floquet topological edge modes
• Emergent Weyl nodes and Fermi arcs in a Floquet Weyl semimetal
• Floquet Semimetal with Floquet-band Holonomy
• Floquet Weyl Phases in a Three Dimensional Network Model
• Three-dimensional Chiral Lattice Fermion in Floquet Systems
• Generating controllable type-II Weyl points via periodic driving
• A computational study of two-terminal transport of Floquet quantum Hall insulators
• Kicked-Harper model vs On-Resonance Double Kicked Rotor Model: From Spectral Difference to Topological Equivalence
• Line nodes and surface Majorana flat bands in static and kicked p-wave superconducting Harper model
• Photoinduced $\frac{1}{2}\frac{e^2}{h}$ and $\frac{3}{2}\frac{e^2}{h}$ conductance plateaus in topological insulator-superconductor heterostructures
• Counter-propagating edge states in Floquet topological insulating phases
• Floquet and Anomalous Floquet Weyl Semimetals
• Efficient computation of the $W_3$ topological invariant and application to Floquet-Bloch systems

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• Laser induced surface magnetization in Floquet-Weyl semimetals
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• Emergent topological phases and coexistence of gapless and spectral-localized Floquet quantum spin Hall states via electron-phonon interaction
• Floquet-Weyl semimetals generated by an optically resonant interband-transition
• Symmetry-protected topological corner modes in a periodically driven interacting spin lattice