An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Topological charge pumping with subwavelength Raman lattices

Published

Author(s)

Ian Spielman, Gediminas Juzeliunas, Domantas Burba, mantas Raciunas

Abstract

Recent experiments demonstrated deeply subwavelength lattices using atoms with $N$ internal states Raman-coupled with lasers of wavelength $\lambda$. The resulting unit cell was $\lambda/2N$ in extent, an $N$-fold reduction compared to the usual $\lambda/2$ periodicity of an optical lattice. For resonant Raman coupling, this lattice consists of $N$ independent sinusoidal potentials (with period $\lambda/2$) displaced by $\lambda/2N$ from each other. We show that detuning from Raman resonance induces tunneling between these potentials. Temporally modulating the detuning couples the $s$- and $p$-bands of the potentials, creating a pair of coupled subwavelength Rice--Mele chains. This operates as a novel topological charge pump that counter-intuitively can give half the displacement per pump cycle of each individual Rice--Mele chain separately. We analytically describe this behavior in terms of infinite-system Chern numbers, and numerically identify the associated finite-system edge states.
Citation
Physical Review A (Atomic, Molecular and Optical Physics)

Keywords

Quantum geometry, topology, Quantum Hall, Bose-Einstein condensate

Citation

Spielman, I. , Juzeliunas, G. , Burba, D. and Raciunas, M. (2023), Topological charge pumping with subwavelength Raman lattices, Physical Review A (Atomic, Molecular and Optical Physics), [online], https://doi.org/10.1103/PhysRevA.107.023309, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=935761 (Accessed April 2, 2023)
Created February 15, 2023