Controllable Superconducting Qubit Design based on the Cooper Pair Wavefunction Approach

Recently Prof. John Martinis, 2025 Nobel Laureate, emphasized manufacturing of good superconducting qubit in a scalable way [1]. For this purpose, we use the Cooper Pair wavefunction (CPW) approach for the design of controllable superconducting qubits. Previously, this CPW approach was successfully applied to the DC Josephson effect and explained the Threshold resistance, corresponding to the maximum insulator thickness of the Josephson tunnel junction, over which the Josephson effect disappears, which was found in experiments [2]. We consider the optimum geometrical design of the superconducting qubit, such as the shape and size of aluminum and the insulator thickness and geometry on the nanometer scale. We also calculate quantized energy levels of the superconducting qubit, employing the CPW approach.



[1]. From the First Qubit to Qolab: John Martinis on Building Scalable Quantum Systems,

https://youtu.be/uEpBLHoeZ20?si=Qlq9oHe-XgerKX7t

[2]. Y-J Kim, Cooper Pair Wavefunction Approach to the Josephson Effect, J. Appl. Phys. 103, 103902 (2008)