Robust Preparation of Many-body Ground States in Jaynes-Cummings Lattices

TL;DR

This paper introduces a robust method for preparing many-body ground states of polaritons in Jaynes-Cummings lattices using optimized nonlinear ramping, significantly improving fidelity for quantum simulations.

Contribution

It develops an optimized nonlinear ramping approach based on Landau-Zener estimation to enhance state preparation fidelity in finite-sized JC lattices.

Findings

Fidelity can be maintained near unity across most parameters.

Optimal ramping trajectories significantly improve state preparation accuracy.

Method is applicable to practical quantum simulators.

Abstract

Strongly-correlated polaritons in Jaynes-Cummings (JC) lattices can exhibit quantum phase transitions between the Mott-insulating and superfluid phases at integer fillings. The prerequisite to observe such phase transitions is to pump polariton excitations into a JC lattice and prepare them into appropriate ground states. Despite previous efforts, it is still challenging to generate many-body states with high accuracy. Here we present an approach for the robust preparation of many-body ground states of polaritons in finite-sized JC lattices by optimized nonlinear ramping. We apply a Landau-Zener type of estimation to this finite-sized system and derive the optimal ramping index for selected ramping trajectories, which can greatly improve the fidelity of the prepared states. With numerical simulation, we show that by choosing an appropriate ramping trajectory, the fidelity in this approach can remain close to unity in almost the entire parameter space. This approach can shed light on high-fidelity state preparation in quantum simulators and advance the implementation of quantum simulation with practical devices.