Improved method for measuring tunneling conductance
- 1 October 1980
- journal article
- research article
- Published by AIP Publishing in Review of Scientific Instruments
- Vol. 51 (10) , 1411-1412
- https://doi.org/10.1063/1.1136085
Abstract
An improved electronic circuit has been used to measure tunneling conductance, dI/dV, and its derivative, d2I/dV2 as a function of applied voltage for superconducting junctions. The configuration described permits four‐terminal measurements. A harmonic excitation voltage applied to the sample has low noise (1/2) and low second harmonic contamination (−3%). One unique feature is the use of a digitally switched analog gate in a feedback circuit in order to maintain a constant excitation level over a wide range of dynamic resistance exhibited by typical samples. Furthermore, a balanced bridge circuit is not required and both dI/dV and d2I/dV2 can be measured simultaneously. Alternatively, one can measure dV/dI and d2V/dI2.Keywords
This publication has 1 reference indexed in Scilit:
- A new approach to high resolution measurements of structure in superconducting tunneling currentsReview of Scientific Instruments, 1974