Selective band interaction and long-range hopping in a structured environment with giant atoms

TL;DR

This paper explores how giant atoms in a structured environment can selectively interact with different energy bands and enable high-fidelity long-range hopping, advancing quantum information processing capabilities.

Contribution

It introduces a novel cross-stitch ladder lattice model showing selective band interaction and long-range hopping facilitated by giant atoms with controllable phase.

Findings

Giant atoms can selectively couple to dispersive or flat bands.

Controlled phase modulation enables exclusive interaction with specific bands.

Giant atoms facilitate high-fidelity long-range hopping and energy exchange.

Abstract

Giant atoms, which couple to the environment at multiple discrete points, exhibit various nontrivial phenomena in quantum optics due to their nonlocal couplings. In this study, we propose a one-dimensional cross-stitch ladder lattice featuring both a dispersive band and a flat band. By modulating the relative phase between the coupling points, the giant atom selectively interacts with either band. First, we analyze the scenario where the dispersive and flat bands intersect at two points, and the atomic frequency lies within the band. Unlike the small atom, which simultaneously interacts with both bands, a single giant atom with a controllable phase interacts exclusively with the dispersive or flat band. Second, in the bandgap regime, where two atoms interact through bound-state overlaps manifesting as dipole-dipole interactions, we demonstrate that giant atoms enable deterministic long-range hopping and energy exchange with higher fidelity compared to small atoms. These findings provide promising applications in quantum information processing, offering enhanced controllability and selectivity for quantum systems and devices.