Efficient, stabilized two-qubit gates on a trapped-ion quantum computer

TL;DR

This paper introduces two novel methods for designing efficient, robust two-qubit entangling gates in trapped-ion quantum computers, significantly reducing power consumption and increasing resilience to experimental drift.

Contribution

It presents exact and approximate linear methods for constructing optimal entangling pulses that are more power-efficient and robust than standard approaches.

Findings

Power consumption reduced by over an order of magnitude.

Enhanced robustness to mode drift demonstrated.

Trade-offs between power, gate time, and connectivity explored.

Abstract

Quantum computing is currently limited by the cost of two-qubit entangling operations. In order to scale up quantum processors and achieve a quantum advantage, it is crucial to economize on the power requirement of two-qubit gates, make them robust to drift in experimental parameters, and shorten the gate times. In this paper, we present two methods, one exact and one approximate, to construct optimal pulses for entangling gates on a pair of ions within a trapped ion chain, one of the leading quantum computing architectures. Our methods are direct, non-iterative, and linear, and can construct gate-steering pulses requiring less power than the standard method by more than an order of magnitude in some parameter regimes. The power savings may generally be traded for reduced gate time and greater qubit connectivity. Additionally, our methods provide increased robustness to mode drift. We illustrate these trade-offs on a trapped-ion quantum computer.