Landau-Zener Interference in Multilevel Superconducting Flux Qubits Driven by Large Amplitude Fields

TL;DR

This paper presents an analytical model for Landau-Zener interference in multilevel superconducting flux qubits under large amplitude driving, matching experimental results and exploring effects of frequency and dephasing.

Contribution

It introduces a new analytical approach to understanding Landau-Zener interference in multilevel flux qubits, aligning with experimental observations.

Findings

Dephasing destroys interference patterns

Increasing driving frequency can restore interference at high dephasing

Interference exhibits anomalous features at specific frequencies and dephasing rates

Abstract

We proposed an analytical model to analyze the Landau-Zener interference in a multilevel superconducting flux qubit driven by large amplitude external fields. Our analytical results agree remarkably with those of the experiment [Nature 455, 51 (2008)]. Moreover, we studied the effect of driving-frequency and dephasing rate on the interference. The dephasing generally destroys the interference while increasing frequency rebuilds the interference at large dephasing rate. At certain driving frequency and dephasing rate, the interference shows some anomalous features as observed in recent experiments.