We employed a scanning Hall probe microscope to detect the hopping of individual vortices between pinning sites along grain boundaries in thin films in the presence of an applied current. Detecting the motion of individual vortices allowed us to probe the current-voltage characteristics of the grain boundary with voltage sensitivity below a femtovolt. We find a very sharp onset of dissipation with with an unprecedented high exponent of that shows essentially no dependence on temperature or grain boundary angle. Our data have no straightforward explanation within the existing grain boundary transport models.
REFERENCES
1.
H.
Hilgenkamp
and J.
Mannhart
, Rev. Mod. Phys.
74
, 485
(2002
).2.
C. C.
Tsuei
et al., Phys. Rev. Lett.
73
, 593
(1994
).3.
C. C.
Tsuei
and J. R.
Kirtley
, Rev. Mod. Phys.
72
, 969
(2000
).4.
5.
H.
Safar
et al., Phys. Rev. Lett.
68
, 2672
(1992
).6.
F. C.
Wellstood
et al., Phys. Rev. Lett.
70
, 89
(1993
).7.
E.
Sandvold
and C.
Rossel
, Physica C
190
, 309
(1992
).8.
I. L.
Landau
and H. R.
Ott
, Physica C
340
, 251
(2000
).9.
R. B.
Dinner
, M. R.
Beasley
, and K. A.
Moler
, Rev. Sci. Instrum.
76
, 103702
(2005
).10.
J.
Mannhart
et al., Phys. Rev. Lett.
61
, 2476
(1988
).11.
D.
Winkler
et al., Phys. Rev. Lett.
72
, 1260
(1994
).12.
N. F.
Heinig
et al., Phys. Rev. B
60
, 1409
(1999
).13.
A.
Diaz
et al., Phys. Rev. B
58
, R2960
(1998
).14.
D.
Dimos
, P.
Chaudhari
, and J.
Mannhart
, Phys. Rev. B
41
, 4038
(1990
).15.
A.
Gurevich
et al., Phys. Rev. Lett.
88
, 097001
(2002
).16.
R. D.
Redwing
et al., Appl. Phys. Lett.
75
, 3171
(1999
).17.
S. J.
Machlup
, J. Appl. Phys.
25
, 341
(1954
).18.
J. R.
Kirtley
et al., J. Appl. Phys.
63
, 1541
(1988
).19.
Four-probe transport measurements were acquired on a neighboring bridge with identical dimensions and normalized to of that bridge, 34 m A at 10 K, measured with Hall probe.
20.
G.
Blatter
et al., Rev. Mod. Phys.
66
, 1125
(1994
).21.
E.
Zeldov
et al., Appl. Phys. Lett.
56
, 1700
(1990
).22.
A.
Gurevich
, Phys. Rev. B
65
, 214531
(2002
).23.
D. S.
Fisher
, M. P. A.
Fisher
, and D. A.
Huse
, Phys. Rev. B
43
, 130
(1991
).24.
See EPAPS Document No. E-APPLAB-94-038920 for a file that describes an estimation of the quantum tunneling rate of Josephson vortices in our GB geometry. For more information on EPAPS, see http://www.aip.org/pubservs/epaps.html.
© 2009 American Institute of Physics.
2009
American Institute of Physics
You do not currently have access to this content.
