Report
Controlling the thickness of Josephson tunnel barriers with atomic layer deposition
| العنوان: | Controlling the thickness of Josephson tunnel barriers with atomic layer deposition |
|---|---|
| المؤلفون: | Elliot, Alan J., Ma, Chunrui, Lu, Rongtao, Xin, Melisa, Han, Siyuan, Wu, Judy Z., Sakidja, Ridwan, Yu, Haifeng |
| سنة النشر: | 2014 |
| المجموعة: | Condensed Matter |
| مصطلحات موضوعية: | Condensed Matter - Superconductivity, Condensed Matter - Materials Science |
| الوصف: | Atomic Layer Deposition (ALD) is a promising technique for producing Josephson junctions (JJs) with lower defect densities for qubit applications. A key problem with using ALD for JJs is the interfacial layer (IL) that develops underneath the tunnel barrier. An IL up to 2 nm forms between ALD Al2O3 and Al. However, the IL thickness is unknown for ALD films less 1 nm. In this work, Nb-Al-ALD-Al2O3-Nb trilayers with tunnel barriers from 0.6 - 1.6 nm were grown in situ. Nb-Al-AlOx-Nb JJs with thermally oxidized tunnel barrier were produced for reference. RN was obtained using a four-point method at 300 K. JC, and its dependence on barrier thickness, was calculated from the Ambegaokar-Baratoff formula. The Al surface was modeled using ab initio molecular dynamics to study the nucleation of Al2O3 on Al. Current voltage characteristics were taken at 4 K to corroborate the room temperature measurements. Together, these results suggest that ALD may be used to grow an ultrathin, uniform tunnel barrier with controllable tunnel resistance and JC, but a thin IL develops during the nucleation stage of ALD growth that may disqualify Al as a suitable wetting layer for ALD JJ based qubits. Comment: 5 pages, 4 figures, Applied Superconductivity Conference |
| نوع الوثيقة: | Working Paper |
| URL الوصول: | http://arxiv.org/abs/1408.3077 |
| رقم الانضمام: | edsarx.1408.3077 |
| قاعدة البيانات: | arXiv |
| الوصف غير متاح. |