Effective non-local parity-dependent couplings in qubit chains

TL;DR

This paper introduces a method for engineering non-local parity-dependent couplings in qubit chains, enabling efficient multi-qubit operations and simulations with high fidelity in superconducting circuits.

Contribution

It presents a novel approach to generate long-range, parity-dependent couplings in qubit chains, useful for various quantum computing tasks.

Findings

High gate fidelity (>99.9%) achieved in simulations

Effective implementation of Trotter-step for Jordan-Wigner fermions

Versatile applications including quantum simulation and error correction

Abstract

For the efficient implementation of quantum algorithms, practical ways to generate many-body entanglement are a basic requirement. Specifically, coupling multiple qubit pairs at once can be advantageous and can lead to multi-qubit operations useful in the construction of hardware-tailored algorithms. Here we harness the simultaneous coupling of qubits on a chain and engineer a set of non-local parity-dependent quantum operations suitable for a wide range of applications. The resulting effective long-range couplings directly implement a parametrizable Trotter-step for Jordan-Wigner fermions and can be used for simulations of quantum dynamics, efficient state generation in variational quantum eigensolvers, parity measurements for error-correction schemes, and the generation of efficient multi-qubit gates. Moreover, we present numerical simulations of the gate operation in a superconducting quantum circuit architecture, which show a high gate fidelity of $>99.9\%$ for realistic experimental parameters.