Toward hybrid quantum simulations with qubits and qumodes on trapped-ion platforms

TL;DR

This paper investigates the potential of hybrid quantum computing on trapped-ion platforms by combining qubits and qumodes, demonstrating high-fidelity operations and exploring applications in quantum simulation of complex models.

Contribution

It introduces the feasibility of hybrid quantum gates on trapped ions and develops a variational algorithm for simulating the Jaynes-Cummings-Hubbard model.

Findings

High-fidelity hybrid gates achievable on current platforms

Successful classical simulation of the Jaynes-Cummings-Hubbard model

Development of a variational algorithm for ground state preparation

Abstract

We explore the feasibility of gate-based hybrid quantum computing using both discrete (qubit) and continuous (qumode) variables on trapped-ion platforms. Trapped-ion systems have demonstrated record one- and two-qubit gate fidelities and long qubit coherence times, while qumodes, which can be represented by the collective vibrational modes of the ion chain, have remained relatively unexplored for their use in computing. Using numerical simulations, we show that high-fidelity hybrid gates and measurement operations can be achieved for existing trapped-ion quantum platforms. As an exemplary application, we consider quantum simulations of the Jaynes-Cummings-Hubbard model, which is given by a one-dimensional chain of interacting spin and boson degrees of freedom. Using classical simulations, we study its real-time evolution and develop a suitable variational quantum algorithm for ground state preparation. Our results motivate further studies of hybrid quantum computing in this context, which may lead to direct applications in condensed matter and fundamental particle and nuclear physics.