偵測約瑟夫森結內的量子能階

Detection of Quantum States in a Josephson Junction

吳岱洋(Wu Tai-Yang)

指導教授 ： 李定國

共同指導教授 ： 陳啟東(Chen Chii-Dong)

國立臺灣大學/理學院/物理研究所/碩士(2011年)

https://doi.org/10.6342/NTU.2011.10068

摘要

我們以SQUID當作可調控的電磁環境，探討Small Josephson Junction在不同環境下的I-V特性。觀察到當Cooper Pair於Small Junction兩端的能量差等同於SQUID的能階差時，有額外的穿隧電流出現，此現象可以P(E)理論描述之。此外，SQUID的IC隨外加磁場強度的改變能夠定量地表示，而IC與SQUID能階差的關係也和理論相符。

關鍵字

鋁 ； 約瑟夫森結 ； 單電子電晶體 ； 超導量子干涉元件 ； 古柏對 ； 穿隧 ； 微影技術

並列摘要

Using SQUIDs as a tunable electromagnetic environment, we discussed the I-V characteristic of a small Josephson junction in different environments. An additional tunneling current was observed while the energy difference of a Cooper pair tunneling through the small Josephson junction matched the level spacing of SQUIDs. This could be described using the P(E) theory. Furthermore, the measured Ic of the SQUID versus the external magnetic field could be described quantitatively; and experimental results of the IC and the level spacing of the SQUID were in an agreement with theories.

並列關鍵字

aluminum ； Josephson junction ； single-electron transistor ； superconducting quantum interference device ； Cooper pair ； tunneling ； lithography

參考文獻

10. 陳啟東，吳憲昌, 以電子顯微鏡為基礎之電子束曝光機的改裝與應用. 科儀新知, 2005. 第二十六卷(第六期): p. 63-72.

1. Lindell, R., et al., Quantum states of a mesoscopic SQUID measured using a small Josephson junction. PHYSICAL REVIEW B, 2003. 68(5): p. 052506.

2. Watanabe, M., Single-electron transistors in electromagnetic environments. PHYSICAL REVIEW B, 2004. 69(9): p. 094509.

3. Monaco, R., et al., Static properties of small Josephson tunnel junctions in an oblique magnetic field. PHYSICAL REVIEW B, 2009. 79(14): p. 144521.

4. Ingold, G.L. and Y.V. Nazarov, Single Charge Tunneling: Coulomb Blockade Phenomena in Nanostructures, edited by H. Grabert and M. H. Devoret. Plenum, New York, 1992. Chapter 2.