Amplifying Decoherence-Free Many-Body Interactions with Giant Atoms Coupled to Parametric Waveguide

TL;DR

This paper introduces a scalable quantum platform combining giant atoms with traveling-wave parametric waveguides to enhance and protect many-body interactions from noise, enabling advanced quantum simulations.

Contribution

It extends squeezing-amplified interactions to giant atoms coupled with nonlinear waveguides, achieving noise immunity and tunable many-body interactions for scalable quantum simulation.

Findings

Enhanced atom-atom interactions via destructive interference.

Immunity to squeezed noise in giant atom systems.

Tunable interaction strengths through squeezing parameters.

Abstract

Parametric amplification offers a powerful means to enhance quantum interactions through field squeezing, yet it typically introduces additional noise which accelerates quantum decoherence, a major obstacle for scalable quantum information processing. The squeezing field is implemented in cavities rather than continuous waveguides, thereby limiting its scalability for applications in quantum simulation. Giant atoms, which couple to waveguides at multiple points, provide a promising route to mitigate dissipation via engineered interference, enabling decoherence-free interactions. We extend the squeezing-amplified interaction to a novel quantum platform combining giant atoms with traveling-wave parametric waveguides based on $\chi^{(2)}$ nonlinearity. By exploiting destructive interference between different coupling points, the interaction between giant atoms is not only significantly enhanced but also becomes immune to squeezed noise. Unlike conventional waveguide quantum electrodynamics without a squeezing pump, the giant emitters exhibit both exchange and pairing interactions, making this platform particularly suitable for simulating many-body quantum physics. More intriguingly, the strengths of these interactions can be smoothly tuned by adjusting the squeezing and coupling parameters. Our architecture thus provides a versatile and scalable platform for quantum simulation of strongly correlated physics and paves the way toward robust quantum control in many-body regimes.