Parallel Entangling Operations on a Universal Ion Trap Quantum Computer

TL;DR

This paper demonstrates the first experimental implementation of parallel entangling gates on a fully-connected ion trap quantum computer, enabling faster quantum circuits and advancing fault-tolerant quantum computing.

Contribution

It presents the first experimental realization of parallel 2-qubit entangling gates in a fully-connected ion trap system, showcasing improved quantum circuit efficiency.

Findings

Successful implementation of parallel entangling gates

Execution of a quantum full adder circuit with reduced depth

Advancement towards fault-tolerant quantum computing

Abstract

The circuit model of a quantum computer consists of sequences of gate operations between quantum bits (qubits), drawn from a universal family of discrete operations. The ability to execute parallel entangling quantum gates offers clear efficiency gains in numerous quantum circuits as well as for entire algorithms such as Shor's factoring algorithm and quantum simulations. In cases such as full adders and multiple-control Toffoli gates, parallelism can provide an exponential improvement in overall execution time. More importantly, quantum gate parallelism is essential for the practical fault-tolerant error correction of qubits that suffer from idle errors. The implementation of parallel quantum gates is complicated by potential crosstalk, especially between qubits fully connected by a common-mode bus, such as in Coulomb-coupled trapped atomic ions or cavity-coupled superconducting transmons. Here, we present the first experimental results for parallel 2-qubit entangling gates in an array of fully-connected trapped ion qubits. We demonstrate an application of this capability by performing a 1-bit full addition operation on a quantum computer using a depth-4 quantum circuit. These results exploit the power of highly connected qubit systems through classical control techniques, and provide an advance toward speeding up quantum circuits and achieving fault tolerance with trapped ion quantum computers.