### Abstract

We study the single-particle properties of a system formed by ultracold atoms loaded into the manifold of l=1 orbital angular momentum (OAM) states of an optical lattice with a diamond-chain geometry. Through a series of successive basis rotations, we show that the OAM degree of freedom induces phases in some tunneling amplitudes of the tight-binding model that are equivalent to a net π flux through the plaquettes. These effects give rise to a topologically nontrivial band structure and protected edge states which persist everywhere in the parameter space of the model, indicating the absence of a topological transition. By taking advantage of these analytical mappings, we also show that this system constitutes a realization of a square-root topological insulator. In addition, we demonstrate that quantum interferences between the different tunneling processes involved in the dynamics may lead to Aharanov-Bohm caging in the system. All these analytical results are confirmed by exact diagonalization numerical calculations.

Language | English |
---|---|

Article number | 023612 |

Number of pages | 12 |

Journal | Physical Review A |

Volume | 99 |

Issue number | 2 |

DOIs | |

Publication status | Published - 11 Feb 2019 |

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### Keywords

- ingle-particle properties
- ultracold atoms
- orbital angular momentum
- OAM

### Cite this

*Physical Review A*,

*99*(2), [023612]. https://doi.org/10.1103/PhysRevA.99.023612

}

*Physical Review A*, vol. 99, no. 2, 023612. https://doi.org/10.1103/PhysRevA.99.023612

**Topological edge states with ultracold atoms carrying orbital angular momentum in a diamond chain.** / Pelegrí, G.; Marques, A. M.; Dias, R. G.; Daley, A. J.; Ahufinger, V.; Mompart, J.

Research output: Contribution to journal › Article

TY - JOUR

T1 - Topological edge states with ultracold atoms carrying orbital angular momentum in a diamond chain

AU - Pelegrí, G.

AU - Marques, A. M.

AU - Dias, R. G.

AU - Daley, A. J.

AU - Ahufinger, V.

AU - Mompart, J.

PY - 2019/2/11

Y1 - 2019/2/11

N2 - We study the single-particle properties of a system formed by ultracold atoms loaded into the manifold of l=1 orbital angular momentum (OAM) states of an optical lattice with a diamond-chain geometry. Through a series of successive basis rotations, we show that the OAM degree of freedom induces phases in some tunneling amplitudes of the tight-binding model that are equivalent to a net π flux through the plaquettes. These effects give rise to a topologically nontrivial band structure and protected edge states which persist everywhere in the parameter space of the model, indicating the absence of a topological transition. By taking advantage of these analytical mappings, we also show that this system constitutes a realization of a square-root topological insulator. In addition, we demonstrate that quantum interferences between the different tunneling processes involved in the dynamics may lead to Aharanov-Bohm caging in the system. All these analytical results are confirmed by exact diagonalization numerical calculations.

AB - We study the single-particle properties of a system formed by ultracold atoms loaded into the manifold of l=1 orbital angular momentum (OAM) states of an optical lattice with a diamond-chain geometry. Through a series of successive basis rotations, we show that the OAM degree of freedom induces phases in some tunneling amplitudes of the tight-binding model that are equivalent to a net π flux through the plaquettes. These effects give rise to a topologically nontrivial band structure and protected edge states which persist everywhere in the parameter space of the model, indicating the absence of a topological transition. By taking advantage of these analytical mappings, we also show that this system constitutes a realization of a square-root topological insulator. In addition, we demonstrate that quantum interferences between the different tunneling processes involved in the dynamics may lead to Aharanov-Bohm caging in the system. All these analytical results are confirmed by exact diagonalization numerical calculations.

KW - ingle-particle properties

KW - ultracold atoms

KW - orbital angular momentum

KW - OAM

UR - http://www.scopus.com/inward/record.url?scp=85061547587&partnerID=8YFLogxK

UR - https://journals.aps.org/pra/

U2 - 10.1103/PhysRevA.99.023612

DO - 10.1103/PhysRevA.99.023612

M3 - Article

VL - 99

JO - Physical Review A - Atomic, Molecular, and Optical Physics

T2 - Physical Review A - Atomic, Molecular, and Optical Physics

JF - Physical Review A - Atomic, Molecular, and Optical Physics

SN - 1050-2947

IS - 2

M1 - 023612

ER -