Landau-Zener-St\"uckelberg Spectroscopy of a Superconducting Flux Qubit

TL;DR

This paper introduces a novel method using Landau-Zener-Stückelberg interference patterns with triangle pulses to measure the energy spectrum of superconducting flux qubits, simplifying setup and reducing noise.

Contribution

The paper presents a new spectroscopy technique that avoids microwave lines, enabling easier and potentially more accurate energy spectrum measurements of superconducting qubits.

Findings

Successfully extracted energy spectra using the new method.

Reduced experimental complexity by eliminating microwave lines.

Applicable to various quantum systems beyond flux qubits.

Abstract

We proposed a new method to measure the energy spectrum of a superconducting flux qubit. Different from the conventional frequency spectroscopy, a short triangle pulse is used to drive the qubit through the anticrossing and generates Landau-Zener-St\"uckelberg interference patterns, from which the information of the energy spectrum can be extracted. Without installing microwave lines one can simplify the experimental setup and reduce the unwanted effects of noise. Moreover, the method can be applied to other quantum systems, opening the possibility of calibrating and manipulating qubits with linear pulses.