Transport quantum logic gates for trapped ions

TL;DR

This paper introduces transport-based quantum logic gates for trapped ions, reducing laser control complexity and enabling scalable quantum information processing through ion transport and microfabricated magnets.

Contribution

It proposes transport-based quantum gates that simplify laser control and enable scalable, parallel operations in trapped ion quantum computing.

Findings

Transport gates reduce laser control overhead.

Parallel operations with stationary laser beams are feasible.

Magnet-based two-qubit gates can operate without lasers.

Abstract

Many efforts are currently underway to build a device capable of large scale quantum information processing (QIP). Whereas QIP has been demonstrated for a few qubits in several systems, many technical difficulties must be overcome in order to construct a large-scale device. In one proposal for large-scale QIP, trapped ions are manipulated by precisely controlled light pulses and moved through and stored in multizone trap arrays. The technical overhead necessary to precisely control both the ion geometrical configurations and the laser interactions is demanding. Here we propose methods that significantly reduce the overhead on laser beam control for performing single and multiple qubit operations on trapped ions. We show how a universal set of operations can be implemented by controlled transport of ions through stationary laser beams. At the same time, each laser beam can be used to perform many operations in parallel, potentially reducing the total laser power necessary to carry out QIP tasks. The overall setup necessary for implementing transport gates is simpler than for gates executed on stationary ions. We also suggest a transport-based two-qubit gate scheme utilizing microfabricated permanent magnets that can be executed without laser light.