Superconducting quantum bits<xref rid="cpb_27_2_027401fn1" ref-type="fn">*</xref> <fn id="cpb_27_2_027401fn1"> <label>*</label> <p>Project supported by the National Natural Science Foundation of China (Grant Nos. 91321208 and 11674380) and the National Key Basic Research Program of the Ministry of Science and Technology of China (Grant Nos. 2014CB921202, 2015CB921104, and 2016YFA0300601).</p> </fn>

Superconducting quantum bits* *

Project supported by the National Natural Science Foundation of China (Grant Nos. 91321208 and 11674380) and the National Key Basic Research Program of the Ministry of Science and Technology of China (Grant Nos. 2014CB921202, 2015CB921104, and 2016YFA0300601).

Liu Wei-Yang^{1, 2}, Zheng Dong-Ning^{1, 2}, Zhao Shi-Ping^{1, 2, †}

(color online) (a) The charge qubit schematic. The transmon qubit can be derived by shorting the gate voltage source (V_g = 0). Energy spectra in the cases of E_C ≫ E_J (b) and E_C ≪ E_J (c). (d) Potential well and energy levels of the transmon qubit.