超導量子位元在強驅動下的能階躍遷

電路-量⼦電動⼒學(C-QED) 是研究⼈造原⼦與微波之間交互作⽤的領域，⼈造原⼦是利⽤超導電路製程，我們稱之為超導量⼦位元(transmon)，此系統可以觀察到量⼦光學的現象。本論⽂中探討，在⼀維傳輸線末端的超導量⼦位元(即微波波腹位⼦) 與相⼲微波之間的強耦合的特性來探討量⼦光學效應。⾸先我們測量以外部磁場和相⼲微波探測場頻率為函數的反射係數，然後我們固定在最佳磁通量的偏壓下，測量以相⼲微波探測功率和頻率為函數的反射係數。最後使⽤雙驅動場(弱探測場和強控制場)，透過增加控制場功率觀察特定光譜，當控制場頻率在基態與第⼀激發態的共振頻率下發現Mollow 三重態(Mollow triplet)，當控制場頻率在第⼆激發態與第⼀激發態的共振頻率下發現Autler-twones 分裂(ATS)，當我們進⼀步增加控制場時，可以看到更複雜的結構。

關鍵字

超導量子位元；量子光學； Mollow 三重態； Autler-twones 分裂；電路-量⼦電動⼒學

並列摘要

Circuit quantum electrodynamics(C-QED) is a field that studies the interaction between artificial atoms and microwaves. Artificial atom is made using quantum circuit, this system can be used to investigate the phenomenon of quantum optics. In this thesis, we explore the quantum-optical effect of the strong coupling between transmon at the end of a One-Dimensional transmission line(microwave antinode position) and coherent microwaves. First we measure the reflection coefficient as a function of the external magnetic field, and probe frequency of the coherent microwave field. Then, we fixed at optimal magnetic flux bias, we measure reflection coefficient as a function of power and probe frequency. Finally we use two-tone(weak probe and strong control fields). Spectroscopy in particular by increasing control power, the Autler-twones splitting was observed when the control field frequency resonant with the first and the second excited states. The Mollow triplet were observed when control field frequency resonant with the ground and first excited states. When we further increase control power, we see complex structure.

並列關鍵字

transmon ； quantum optics ； Mollow triplet ； Autler-twones splitting ； C-QED

參考文獻

[1] P. W. Shor. Algorithms for quantum computation: discrete logarithms and factoring. Proceedings of 35th Annual Symposium on Foundations of Com- puter Science, page 124, 1994.