Demonstration of tunable three-body interactions between superconducting qubits

TL;DR

This paper demonstrates a superconducting circuit that can tunably implement three-body interactions between qubits, advancing quantum simulation and computation capabilities.

Contribution

It introduces a novel circuit architecture enabling tunable three-body interactions between superconducting qubits, which was not previously achievable.

Findings

3-local interactions are coherently tunable over several MHz

The system Hamiltonian is characterized via multi-qubit Ramsey interferometry

The coupler flux biases effectively control the interaction strength and turn-off

Abstract

Nonpairwise multi-qubit interactions present a useful resource for quantum information processors. Their implementation would facilitate more efficient quantum simulations of molecules and combinatorial optimization problems, and they could simplify error suppression and error correction schemes. Here we present a superconducting circuit architecture in which a coupling module mediates 2-local and 3-local interactions between three flux qubits by design. The system Hamiltonian is estimated via multi-qubit pulse sequences that implement Ramsey-type interferometry between all neighboring excitation manifolds in the system. The 3-local interaction is coherently tunable over several MHz via the coupler flux biases and can be turned off, which is important for applications in quantum annealing, analog quantum simulation, and gate-model quantum computation.