Current–voltage characteristics of Nb–carbon–Nb junctions

We report on properties of Nb(/Ti)–carbon–(Ti/)Nb junctions fabricated on graphite flakes using e-beam lithography. The devices were characterized at temperatures above 1.8 K where a Josephson current was not observed, but the differential conductivity revealed features below the critical temperatur...

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Published in:Физика низких температур
Date:2014
Main Authors: Nevirkovets, I.P., Shafranjuk, S.E., Chernyashevskyy, O., Masilamani, N., Ketterson, J.B.
Format: Article
Language:English
Published: Фізико-технічний інститут низьких температур ім. Б.І. Вєркіна НАН України 2014
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Online Access:https://nasplib.isofts.kiev.ua/handle/123456789/119426
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Journal Title:Digital Library of Periodicals of National Academy of Sciences of Ukraine
Cite this:Current–voltage characteristics of Nb–carbon–Nb junctions / I.P. Nevirkovets, S.E. Shafranjuk, O. Chernyashevskyy, N. Masilamani, J.B. Ketterson // Физика низких температур. — 2014. — Т. 40, № 3. — С. 250-258. — Бібліогр.: 18 назв. — англ.

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Digital Library of Periodicals of National Academy of Sciences of Ukraine
id nasplib_isofts_kiev_ua-123456789-119426
record_format dspace
spelling Nevirkovets, I.P.
Shafranjuk, S.E.
Chernyashevskyy, O.
Masilamani, N.
Ketterson, J.B.
2017-06-06T19:11:30Z
2017-06-06T19:11:30Z
2014
Current–voltage characteristics of Nb–carbon–Nb junctions / I.P. Nevirkovets, S.E. Shafranjuk, O. Chernyashevskyy, N. Masilamani, J.B. Ketterson // Физика низких температур. — 2014. — Т. 40, № 3. — С. 250-258. — Бібліогр.: 18 назв. — англ.
0132-6414
PACS 72.80.Vp, 74.45.+c, 74.50.+r, 74.78.Na
https://nasplib.isofts.kiev.ua/handle/123456789/119426
We report on properties of Nb(/Ti)–carbon–(Ti/)Nb junctions fabricated on graphite flakes using e-beam lithography. The devices were characterized at temperatures above 1.8 K where a Josephson current was not observed, but the differential conductivity revealed features below the critical temperature of Nb, and overall metallic conductivity, in spite of a high-junctions resistance. Since the conductivity of graphite along the planes is essentially two-dimensional (2D), we use a theoretical model developed for metal/graphene junctions for interpretation of the results. The model involves two very different graphene “access” lengths. The shorter length characterizes ordinary tunneling between the three-dimensional Nb(/Ti) electrode and 2D graphene, while the second, much longer length, is associated with the Andreev reflections (AR) inside the junction and involves also “reflectionless” AR processes. The relevant transmission factors are small in the first case and much larger in the second, which explains the apparent contradiction of the observed behaviors
en
Фізико-технічний інститут низьких температур ім. Б.І. Вєркіна НАН України
Физика низких температур
Свеpхпpоводимость, в том числе высокотемпеpатуpная
Current–voltage characteristics of Nb–carbon–Nb junctions
Article
published earlier
institution Digital Library of Periodicals of National Academy of Sciences of Ukraine
collection DSpace DC
title Current–voltage characteristics of Nb–carbon–Nb junctions
spellingShingle Current–voltage characteristics of Nb–carbon–Nb junctions
Nevirkovets, I.P.
Shafranjuk, S.E.
Chernyashevskyy, O.
Masilamani, N.
Ketterson, J.B.
Свеpхпpоводимость, в том числе высокотемпеpатуpная
title_short Current–voltage characteristics of Nb–carbon–Nb junctions
title_full Current–voltage characteristics of Nb–carbon–Nb junctions
title_fullStr Current–voltage characteristics of Nb–carbon–Nb junctions
title_full_unstemmed Current–voltage characteristics of Nb–carbon–Nb junctions
title_sort current–voltage characteristics of nb–carbon–nb junctions
author Nevirkovets, I.P.
Shafranjuk, S.E.
Chernyashevskyy, O.
Masilamani, N.
Ketterson, J.B.
author_facet Nevirkovets, I.P.
Shafranjuk, S.E.
Chernyashevskyy, O.
Masilamani, N.
Ketterson, J.B.
topic Свеpхпpоводимость, в том числе высокотемпеpатуpная
topic_facet Свеpхпpоводимость, в том числе высокотемпеpатуpная
publishDate 2014
language English
container_title Физика низких температур
publisher Фізико-технічний інститут низьких температур ім. Б.І. Вєркіна НАН України
format Article
description We report on properties of Nb(/Ti)–carbon–(Ti/)Nb junctions fabricated on graphite flakes using e-beam lithography. The devices were characterized at temperatures above 1.8 K where a Josephson current was not observed, but the differential conductivity revealed features below the critical temperature of Nb, and overall metallic conductivity, in spite of a high-junctions resistance. Since the conductivity of graphite along the planes is essentially two-dimensional (2D), we use a theoretical model developed for metal/graphene junctions for interpretation of the results. The model involves two very different graphene “access” lengths. The shorter length characterizes ordinary tunneling between the three-dimensional Nb(/Ti) electrode and 2D graphene, while the second, much longer length, is associated with the Andreev reflections (AR) inside the junction and involves also “reflectionless” AR processes. The relevant transmission factors are small in the first case and much larger in the second, which explains the apparent contradiction of the observed behaviors
issn 0132-6414
url https://nasplib.isofts.kiev.ua/handle/123456789/119426
fulltext
citation_txt Current–voltage characteristics of Nb–carbon–Nb junctions / I.P. Nevirkovets, S.E. Shafranjuk, O. Chernyashevskyy, N. Masilamani, J.B. Ketterson // Физика низких температур. — 2014. — Т. 40, № 3. — С. 250-258. — Бібліогр.: 18 назв. — англ.
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first_indexed 2025-11-24T04:21:00Z
last_indexed 2025-11-24T04:21:00Z
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