La Trobe
1156129_Valdes-Curiel_2021.pdf (2.72 MB)

Topological features without a lattice in Rashba spin-orbit coupled atoms

Download (2.72 MB)
journal contribution
posted on 08.03.2021, 04:32 by A Valdés-Curiel, D Trypogeorgos, Q-Y Liang, Russell Anderson, IB Spielman
AbstractTopological order can be found in a wide range of physical systems, from crystalline solids, photonic meta-materials and even atmospheric waves to optomechanic, acoustic and atomic systems. Topological systems are a robust foundation for creating quantized channels for transporting electrical current, light, and atmospheric disturbances. These topological effects are quantified in terms of integer-valued ‘invariants’, such as the Chern number, applicable to the quantum Hall effect, or the Z2 invariant suitable for topological insulators. Here, we report the engineering of Rashba spin-orbit coupling for a cold atomic gas giving non-trivial topology, without the underlying crystalline structure that conventionally yields integer Chern numbers. We validated our procedure by spectroscopically measuring both branches of the Rashba dispersion relation which touch at a single Dirac point. We then measured the quantum geometry underlying the dispersion relation using matter-wave interferometry to implement a form of quantum state tomography, giving a Berry’s phase with magnitude π. This implies that opening a gap at the Dirac point would give two dispersions (bands) each with half-integer Chern number, potentially implying new forms of topological transport.

History

Publication Date

01/12/2021

Journal

Nature Communications

Volume

12

Issue

1

Article Number

593

Publisher

Springer Science and Business Media LLC

Rights Statement

The Author reserves all moral rights over the deposited text and must be credited if any re-use occurs. Documents deposited in OPAL are the Open Access versions of outputs published elsewhere. Changes resulting from the publishing process may therefore not be reflected in this document. The final published version may be obtained via the publisher’s DOI. Please note that additional copyright and access restrictions may apply to the published version.

Licence

Exports

Journal Articles

Categories

Licence

Exports