Enhanced connectivity of quantum hardware with digital-analog control

TL;DR

This paper introduces a hybrid digital-analog quantum algorithm that enhances qubit connectivity in superconducting quantum hardware, improving the efficiency and robustness of quantum computations by combining analog evolution with digital control.

Contribution

It proposes a novel hybrid algorithm that increases qubit connectivity and optimizes simulation time using a combination of digital and analog quantum operations.

Findings

Enhances qubit connectivity using hybrid digital-analog methods.

Optimizes quantum simulation in time and resource efficiency.

Improves hardware robustness and algorithm performance.

Abstract

Quantum computers based on superconducting circuits are experiencing a rapid development, aiming at outperforming classical computers in certain useful tasks in the near future. However, the currently available chip fabrication technologies limit the capability of gathering a large number of high-quality qubits in a single superconducting chip, a requirement for implementing quantum error correction. Furthermore, achieving high connectivity in a chip poses a formidable technological challenge. Here, we propose a hybrid digital-analog quantum algorithm that enhances the physical connectivity among qubits coupled by an arbitrary inhomogeneous nearest-neighbour Ising Hamiltonian and generates an arbitrary all-to-all Ising Hamiltonian only by employing single-qubit rotations. Additionally, we optimize the proposed algorithm in the number of analog blocks and in the time required for the simulation. These results take advantage of the natural evolution of the system by combining the flexibility of digital steps with the robustness of analog quantum computing, allowing us to improve the connectivity of the hardware and the efficiency of quantum algorithms.