Method for identifying electromagnetically induced transparency in a tunable circuit quantum electrodynamics system

TL;DR

This paper demonstrates the experimental observation of electromagnetically induced transparency (EIT) in a tunable superconducting transmon system, distinguishing EIT from Autler-Townes splitting and analyzing the transition between regimes.

Contribution

It introduces a method to identify EIT in a tunable circuit quantum electrodynamics system and compares different thresholds for EIT-ATS transition using Akaike information criterion.

Findings

EIT observed in a tunable transmon via cavity transmission

Identification of EIT, ATS, and transition regimes

Akaike information criterion better describes EIT-ATS transition

Abstract

Electromagnetically induced transparency (EIT) has been realized in atomic systems, but fulfilling the EIT conditions for artificial atoms made from superconducting circuits is a more difficult task. Here we report an experimental observation of the EIT in a tunable three-dimensional transmon by probing the cavity transmission. To fulfill the EIT conditions, we tune the transmon to adjust its damping rates by utilizing the effect of the cavity on the transmon states. From the experimental observations, we clearly identify the EIT and Autler-Townes splitting (ATS) regimes as well as the transition regime in between. Also, the experimental data demonstrate that the threshold $\Omega_{\rm AIC}$ determined by the Akaike information criterion can describe the EIT-ATS transition better than the threshold $\Omega_{\rm EIT}$ given by the EIT theory.