Nanoscale microbridges made of NbN granular thin films were fabricated by the edge‐defined process. The diameter of NbN grains is ∼8 nm, and the size of the microbridges is ∼50 nm in width and ∼200 nm in length. We have observed a clear Coulomb blockage at 4.2 K in current–voltage characteristics. In order to investigate electrical field effects, a gate electric field was applied to the microbridge. We observed periodic conductance modulations with the gate voltage period of 15–20 V, from which the gate‐grain capacitance is estimated to be 0.01 aF. The experimental results agree with numerical simulation based on the model of a two‐dimensional array of single‐electron‐tunneling junctions.
REFERENCES
1.
2.
D. V. Averin and K. K. Likharev, in Mesoscopic Phenomena in Solids, edited by B. L. Altshuler, P. A. Lee, and R. A. Webb (North-Holland, Amsterdam, 1991), p. 173.
3.
4.
L. G.
Geeligs,
V. F.
Anderegg,
P. A. M.
Holweg,
J. E.
Mooij,
H.
Pothier,
D.
Esteve,
C.
Urbina
, and M. H.
Devoret,
Phys. Rev. Lett.
64
, 2691
(1990
).5.
H.
Pothier,
P.
Lafarge,
C.
Urbina,
D.
Esteve
, and M. H.
Denoret,
Europhys. Lett.
17
, 249
(1992
).6.
7.
8.
9.
N.
Yoshikawa,
N.
Miura,
X.
Chen,
K.
Yokoyama
, and M.
Sugahara,
IEEE Trans. Appl. Supercond.
5
, 3090
(1995
).10.
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© 1995 American Institute of Physics.
1995
American Institute of Physics
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