  We are suggesting an electronic method for Cooper pair mass spectroscopy of
thin superconducting films. The method can be applied, for example, for 100 nm
thin high-T_c films grown on insulator substrate 10 mm X 10 mm. In Corbino
geometry two Ohmic contacts have to be made on the film evaporating Ag or using
silver paste: one circle with radius r_a (1) and a ring electrode with internal
radius r_b (2). In the in-between space (r_a,r_b) a ring electrode from mylar
assures a capacitive connection between the superconducting layer and the
metallized surface (3) of the mylar. In such a way we have an field effect
transistor (FET) type structure with a circular gate. When at low enough
temperatures T << T_c an AC current with frequency omega is applied between the
circle source (1) and the ring-shaped drain (2) an AC Bernoulli voltage with
double frequency 2f appears between the gate (3) and the source (1). The 2f
signal depends on Cooper pair effective mass and its systematic investigation
gives a Cooper pair mass spectroscopy. In the normal phase 2f gives logarithmic
derivative of the density of states (DOS) with respect of Fermi energy.
Applying a gate voltage in the same structure gives the mobility of the normal
phase.
