Frequency-tunable transmon in a three-dimensional copper cavity *
Pan Jia-Zhenga),c)†, Cao Zhi-Mina),c)†, Fan Yun-Yia),c)†, Zhou Yua),c), Lan Dongb),c), Liu Yu-Haob),c), Chen Zhi-Pinga),c), Li Yong-Chaoa),c), Cao Chun-Haia),c), Xu Wei-Weia),c), Kang Lina),c), Chen Jiana), Yu Hai-Fengb),c), Yu Yangb),c), Sun Guo-Zhua),c), Wu Pei-Henga),c)
       
The ω ge of the qubit as a function of bias voltage. Black circles and red lines indicate the experimental and theoretical ω ge at each bias voltage, respectively. The upper right inset shows the spectrum of the qubit at a bias voltage of 0.38 V. The lower left inset shows the energy relaxation time of the qubit as a function of bias voltage.