Scalable and Programmable Phononic Network with Trapped Ions

TL;DR

This paper demonstrates a scalable, programmable phononic network using trapped ions, enabling deterministic preparation and detection of multi-phonon states with high fidelity, paving the way for advanced quantum information processing.

Contribution

It introduces a minimal-loss, programmable phononic network with up to four modes, overcoming photonic limitations and enabling deterministic state manipulation in trapped ion systems.

Findings

Achieved high-fidelity reconstruction of single- and two-phonon states.

Demonstrated deterministic preparation and detection of phononic states.

Showcased potential for scaling to quantum advantage applications.

Abstract

Controllable bosonic systems can provide post-classical computational power with sub-universal quantum computational capability. A network that consists of a number of bosons evolving through beam-splitters and phase-shifters between different modes, has been proposed and applied to demonstrate quantum advantages. While the network has been implemented mostly in optical systems with photons, recently alternative realizations have been explored, where major limitations in photonic systems such as photon loss, and probabilistic manipulation can be addressed. Phonons, the quantized excitations of vibrational modes, of trapped ions can be a promising candidate to realize the bosonic network. Here, we experimentally demonstrate a minimal-loss phononic network that can be programmed and in which any phononic states are deterministically prepared and detected. We realize the network with up to four collective-vibrational modes, which can be straightforwardly extended to reveal quantum advantage. We benchmark the performance of the network with an exemplary algorithm of tomography for arbitrary multi-mode states with a fixed total phonon number. We obtain reconstruction fidelities of 94.5 $\pm$ 1.95 % and 93.4 $\pm$ 3.15 % for single-phonon and two-phonon states, respectively. Our experiment demonstrates a clear and novel pathway to scale up a phononic network for various quantum information processing beyond the limitations of classical and other quantum systems.