Superconducting surface trap chips for microwave-driven trapped ions

TL;DR

This paper introduces superconducting surface trap chips with high-Q resonators for microwave-driven trapped ion gates, significantly reducing heat and power consumption, and enabling scalable, high-fidelity quantum operations.

Contribution

It presents a novel superconducting trap chip design integrating high-Q resonators to improve power efficiency and scalability of microwave-driven ion quantum gates.

Findings

Achieved substantial magnetic field gradients with superconducting Nb resonators.

Reduced microwave losses compared to conventional metal chips.

Proposed a power-efficient two-qubit gate scheme with sub-milliwatt input power.

Abstract

Microwave-driven trapped ion logic gates offer a promising avenue for advancing beyond laser-based logic operations. In future microwave-based operations, however, the joule heat produced by large microwave currents flowing through narrow microwave electrodes would potentially hinder improvements in gate speed and fidelity. Moreover, scalability, particularly in cryogenic trapped ion systems, is impeded by the excessive joule heat. To address these challenges, we present a novel approach: superconducting surface trap chips that integrate high-$Q$ microwave resonators with large current capacities. Utilizing sub-ampere microwave currents in superconducting Nb resonators, we generate substantial magnetic field gradients with significantly reduced losses compared to conventional metal chips. By harnessing the high $Q$ factors of superconducting resonators, we propose a power-efficient two-qubit gate scheme capable of achieving a sub-milliwatt external microwave input power at a gate Rabi frequency of 1 kHz.