Improving Coherence Time of Superconducting Qubits

Yen-Hsiang Lin^1*, W. J. Yen¹, C. C. Ting¹, Y. H. G. Lin², L. B. Young², W. S. Chen², J. Kwo¹, M. Hong²

¹Department of Physics, National Tsinghua University, Hsinchu, Taiwan
²Department of Physics, National Taiwan University, Taipei, Taiwan

* Presenter:Yen-Hsiang Lin, email:yhlin@phys.nthu.edu.tw

In recent years, superconducting quantum circuits has been demonstrated to be one of the promising candidates of hardware platform for quantum processors with engineerable parameters. However, due to strong coupling to the environment, coherence time of superconducting qubits is one of the main limiting factors for application in quantum information science. To improve the coherence times of superconducting qubits, the main strategies are decoupling qubit transitions from the environments or reducing noise sources of the environments. In this talk, I will introduce how to improve the coherence time by designing new type of superconducting qubits such as Fluxonium superconducting qubits to decoupling from environment. Also, the noise of the environment can be tamed by improving materials, fabrication processes, and measurement setup. I will also introduce our current work of design, fabrication, and measurements of Fluxonium qubits and high internal quality factor of microstrip resonators with aluminum films grown by molecular beam epitaxy (MBE). I will summarize the roadmap of achieving high coherence qubits by combining with these techniques.

Keywords: superconducting qubits, coherence time, fluxonium qubits, molecular beam epitaxy