Topological orbital ladders

Abstract

We unveil a topological phase of interacting fermions on a two-leg ladder of unequal parity orbitals, derived from the experimentally realized double-well lattices by dimension reduction. $Z_2$ topological invariant originates simply from the staggered phases of $sp$-orbital quantum tunneling, requiring none of the previously known mechanisms such as spin-orbit coupling or artificial gauge field. Another unique feature is that upon crossing over to two dimensions with coupled ladders, the edge modes from each ladder form a parity-protected flat band at zero energy, opening the route to strongly correlated states controlled by interactions. Experimental signatures are found in density correlations and phase transitions to trivial band and Mott insulators.

12 pages, 5 figures, Revised title, abstract, and the discussion on Majorana number

References in corpus (17)

• Majorana Fermions and a Topological Phase Transition in Semiconductor-Superconductor Heterostructures
• Classification of topological insulators and superconductors in three spatial dimensions
• Topological Field Theory of Time-Reversal Invariant Insulators
• Single-Atom Resolved Fluorescence Imaging of an Atomic Mott Insulator
• Nearly-flat bands with nontrivial topology
• Non-Abelian Topological Order in S-Wave Superfluids of Ultracold Fermionic Atoms
• Time-resolved Observation and Control of Superexchange Interactions with Ultracold Atoms in Optical Lattices
• Controlled exchange interaction between pairs of neutral atoms in an optical lattice
• A lattice of double wells for manipulating pairs of cold atoms
• Orbital superfluidity in the $P$-band of a bipartite optical square lattice
• Realistic Time-Reversal Invariant Topological Insulators With Neutral Atoms
• Engineering Time-Reversal Invariant Topological Insulators With Ultra-Cold Atoms
• Multi-Component Quantum Gases in Spin-Dependent Hexagonal Lattices
• Optical Flux Lattices for Ultracold Atomic Gases
• Orbital analogue of quantum anomalous Hall effect in $p$-band systems
• Interaction effects and quantum phase transitions in topological insulators
• Rotating Few-body Atomic Systems in the Fractional Quantum Hall Regime

Cited by in corpus (19)

• Non-standard Hubbard models in optical lattices: a review
• PT-Symmetry in Non-Hermitian Su-Schrieffer-Heeger model with complex boundary potentials
• Kaleidoscope of symmetry protected topological phases in one-dimensional periodically modulated lattices
• Constructing a Weyl semimetal by stacking one dimensional topological phases
• Topological Bogoliubov excitations in inversion-symmetric systems of interacting bosons
• Shaping topological properties of the band structures in a shaken optical lattice
• Effects of spin-orbit coupling on the Berezinskii-Kosterlitz-Thouless transition and the vortex-antivortex structure in two-dimensional Fermi gases
• End states in a 1-D topological Kondo insulator
• Topological phases, topological flat bands, and topological excitations in a one-dimensional dimerized lattice with spin-orbit coupling
• Simulation and measurement of the fractional particle number in one-dimensional optical lattices
• Hidden-symmetry-protected topological phases on a one-dimensional lattice
• Magnetic end-states in a strongly-interacting one-dimensional topological Kondo insulator
• Floquet FFLO superfluids and Majorana fermions in a shaken fermionic optical lattice
• Topological states in normal and superconducting $p$-wave chains
• Dimensional evolution between one- and two-dimensional topological phases
• Phases of d-orbital bosons in optical lattices
• One-dimensional s-p superlattice
• Effective orbital ordering in multiwell optical lattices with fermionic atoms
• Hidden chiral symmetry protected $\mathbb{Z}\oplus \mathbb{Z}$ topological insulators in a ladder dimer model