Advantages of superconducting Coulomb-blockade electrometers

Author

Song, D. ; Amar, A. ; Lobb, C.J. ; Wellstood, F.C.

Author_Institution

Dept. of Phys., Maryland Univ., College Park, MD, USA

Volume

5

Issue

2

fYear

1995

fDate

6/1/1995 12:00:00 AM

Firstpage

3085

Lastpage

3089

Abstract

We have measured the current-voltage gate charge characteristics and noise in superconducting Coulomb-blockade electrometers from 50 mK to 1.05 K. The Al-AlO/sub x/-Al junctions in our devices have capacitances which range from 0.3 fF to 1 fF and tunneling resistances from 20 k/spl Omega/ to 200 k/spl Omega/. We find that our normal and superconducting electrometers have comparable charge noise but that the latter have much larger modulation which persists to significantly higher temperatures. The maximum operating temperature in the superconducting state is close to T/sub c/. This behavior Is consistent with a simple model and makes the superconducting electrometer preferable for many applications.<>

Keywords

charge measurement; electrometers; quantum interference phenomena; superconducting device noise; superconducting junction devices; 0.3 to 1 fF; 20 to 200 kohm; 50 mK to 1.05 K; Al-AlO-Al; Al-AlO/sub x/-Al junctions; capacitance; charge noise; current-voltage gate charge characteristics; modulation; superconducting Coulomb-blockade electrometers; tunneling resistance; Capacitance; Charge measurement; Current measurement; Josephson junctions; Noise measurement; Superconducting device noise; Superconductivity; Temperature sensors; Tunneling; Voltage;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/77.403244

Filename

403244