Scalable architecture for trapped-ion quantum computing using RF traps and dynamic optical potentials

TL;DR

This paper introduces a scalable ion-trap quantum computing architecture using dynamic optical potentials to segment large ion crystals into manageable, nearly independent quantum registers, enabling high-fidelity, parallel operations and reconfigurability.

Contribution

The proposed architecture overcomes scaling issues in ion-trap quantum computing by dynamically segmenting ion crystals, facilitating parallel gates and connectivity in large-scale systems.

Findings

Enables parallel entangling gates on segmented ion registers

Provides a protocol to mitigate crosstalk errors

Supports both fault-tolerant and analog quantum computing

Abstract

Qubits based on ions trapped in linear radio-frequency traps form a successful platform for quantum computing, due to their high fidelity of operations, all-to-all connectivity and degree of local control. In principle there is no fundamental limit to the number of ion-based qubits that can be confined in a single 1D register. However, in practice there are two main issues associated with long trapped-ion crystals, that stem from the 'softening' of their modes of motion, upon scaling up: high heating rates of the ions' motion, and a dense motional spectrum; both impede the performance of high-fidelity qubit operations. Here we propose a holistic, scalable architecture for quantum computing with large ion-crystals that overcomes these issues. Our method relies on dynamically-operated optical potentials, that instantaneously segment the ion-crystal into cells of a manageable size. We show that these cells behave as nearly independent quantum registers, allowing for parallel entangling gates on all cells. The ability to reconfigure the optical potentials guarantees connectivity across the full ion-crystal, and also enables efficient mid-circuit measurements. We study the implementation of large-scale parallel multi-qubit entangling gates that operate simultaneously on all cells, and present a protocol to compensate for crosstalk errors, enabling full-scale usage of an extensively large register. We illustrate that this architecture is advantageous both for fault-tolerant digital quantum computation and for analog quantum simulations.