標題: Berezinskii-Kosterlitz-Thouless transition in an Al superconducting nanofilm grown on GaAs by molecular beam epitaxy
作者: Su, Guan-Ming
Wu, Bi-Yi
Fan, Yen-Ting
Kumar, Ankit
Chang, Chau-Shing
Yeh, Ching-Chen
Patel, Dinesh K.
Lin, Sheng-Di
Chow, Lee
Liang, Chi-Te
電子工程學系及電子研究所
Department of Electronics Engineering and Institute of Electronics
關鍵字: nanofilm;superconductivity;aluminum;two-dimensional;GaAs substrate
公開日期: 15-May-2020
摘要: We have performed extensive transport experiments on a 4 nm thick aluminum (Al) superconducting film grown on a GaAs substrate by molecular beam epitaxy (MBE). Nonlinear current-voltage (I-V) measurements on such a MBE-grown superconducting nanofilm show that V similar to I-3, which is evidence for the Berezinskii-Kosterlitz-Thouless (BKT) transition, both in the low-voltage (T-BKT 1.97 K) and high-voltage regions (T-BKT 2.17 K). In order to further study the two regions where the I-V curves are BKT-like, our experimental data are fitted to the temperature-induced vortices/antivortices unbinding model as well as the dynamical scaling theory. It is found that the transition temperature obtained in the high-voltage region is the correct T-BKT as confirmed by fitting the data to the aforementioned models. Our experimental results unequivocally show that I-V measurements alone may not allow one to determine T-BKT for superconducting transition. Therefore, one should try to fit one's results to the temperature-induced vortices/antivortices unbinding model and the dynamical scaling theory to accurately determine T-BKT in a two-dimensional superconductor.
URI: http://dx.doi.org/10.1088/1361-6528/ab71ba
http://hdl.handle.net/11536/153867
ISSN: 0957-4484
DOI: 10.1088/1361-6528/ab71ba
期刊: NANOTECHNOLOGY
Volume: 31
Issue: 20
起始頁: 0
結束頁: 0
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