A Study on Fast Gates for Large-Scale Quantum Simulation with Trapped Ions

TL;DR

This paper explores how fast entangling gates in trapped-ion quantum processors can enable large-scale quantum simulations to outperform classical computers without error correction, emphasizing the importance of gate speed for scalability.

Contribution

It demonstrates that high-fidelity, fast entangling gates can significantly improve the scalability of trapped-ion quantum simulators without requiring error correction.

Findings

Fidelity of around 70% is achievable with pi-pulse infidelities below 10^-5.

Fast gates faster than the trap period are crucial for scalability.

Realistic heating and dephasing rates are considered in the analysis.

Abstract

Large-scale digital quantum simulations require thousands of fundamental entangling gates to construct the simulated dynamics. Despite success in a variety of small-scale simulations, quantum information processing platforms have hitherto failed to demonstrate the combination of precise control and scalability required to systematically outmatch classical simulators. We analyse how fast gates could enable trapped-ion quantum processors to achieve the requisite scalability to outperform classical computers without error correction. We analyze the performance of a large-scale digital simulator, and find that fidelity of around 70% is realizable for pi-pulse infidelities below $10^{-5}$ in traps subject to realistic rates of heating and dephasing. This scalability relies on fast gates: entangling gates faster than the trap period.