DETERMINATION OF THERMOMETRIC PARAMETERS FROM THE CONDUCTANCE CURVE OF THE NORMAL-METAL BASED TUNNEL JUNCTION ARRAY

We propose a method for extracting thermometric parameters from the me asured conductance curve, against bias voltage, of a tunnel junction a rray. Instead of fitting the whole theoretical conductance curve to th e experiment, we perform several polynomial fits to selected bias regi ons. The advantage of this method is that polynomial fits are linear i n their fitting parameters whereas the theoretical form for the conduc tance is inherently nonlinear. This way the proposed method is about t hree orders of magnitude faster than the nonlinear fit. Optimizing thi s polynomial fit procedure is discussed. (C) 1997 Elsevier Science B.V .