Driving superconducting qubits into chaos

TL;DR

This paper investigates the limits of Kerr-cat qubits in superconducting circuits, revealing how increased nonlinearity can induce chaos and affect qubit stability, with implications for quantum computing and chaos research.

Contribution

It identifies the parameter regime where Kerr-cat qubits remain stable and explores how chaos emerges as nonlinearity increases in driven superconducting circuits.

Findings

Increased nonlinearity can induce chaos in Kerr parametric oscillators.

The stability region of Kerr-cat qubits is characterized.

Chaos can be experimentally detected in superconducting circuits.

Abstract

Kerr parametric oscillators are potential building blocks for fault-tolerant quantum computers. They can stabilize Kerr-cat qubits, which offer advantages toward the encoding and manipulation of error-protected quantum information. The recent realization of Kerr-cat qubits made use of the nonlinearity of the SNAIL transmon superconducting circuit and a squeezing drive. Increasing nonlinearities can enable faster gate times, but, as shown here, can also induce chaos and melt the qubit away. We determine the region of validity of the Kerr-cat qubit and discuss how its disintegration could be experimentally detected. The danger zone for parametric quantum computation is also a potential playground for investigating quantum chaos with driven superconducting circuits.