Loading…
Temperature dependence of critical current fluctuations in Nb / AlO x / Nb Josephson junctions
We measured the low frequency critical current noise in Nb / AlO x / Nb Josephson junctions. Unshunted junctions biased above the gap voltage and resistively shunted junctions biased near the critical current I c have been measured. For both, the spectral density of δ I c / I c , S i c ( f ) , is pr...
Saved in:
| Published in: | Applied physics letters 2009-01, Vol.94 (4), p.043501-043501-3 |
|---|---|
| Main Authors: | , , |
| Format: | Article |
| Language: | English |
| Citations: | Items that this one cites |
| Online Access: | Get full text |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | We measured the low frequency critical current noise in
Nb
/
AlO
x
/
Nb
Josephson junctions. Unshunted junctions biased above the gap voltage and resistively shunted junctions biased near the critical current
I
c
have been measured. For both, the spectral density of
δ
I
c
/
I
c
,
S
i
c
(
f
)
, is proportional to
1
/
f
, scales inversely as the area
A
and is independent of
J
c
≡
I
c
/
A
over a factor of nearly 20 in
J
c
. For all devices measured at 4.2 K,
S
i
c
(
1
Hz
)
=
2.0
±
0.4
×
10
−
12
/
Hz
when scaled to
A
=
1
μ
m
2
. We find that, from 4.2 to 0.46 K,
S
i
c
(
f
)
decreases linearly with temperature. |
|---|---|
| ISSN: | 0003-6951 1077-3118 |
| DOI: | 10.1063/1.3074446 |