YBCOSQUIDs fabricated by field-emission electron beam source

We report the applicability of YBa2Cu3O7-y., (YBCO) SQUIDs fabricated by field-emission electron beam source. The junctions show hysteresis and self-resonance steps related to a high frequency resonance in the de SQUID loop at a voltage V-res = Phi(0) / 2 pi(LC / 2)(1/2) around 0.3 T-c, The noise spectrum of the SQUIDs was measured with de-bias schemes at different temperatures and showed values around 10(-4)Phi(0)/Hz(1/2) down to frequencies of 10 Hz at 40 K. The influence of magnetic flux, operating temperatures and flux-voltage transfer factor( \ dV/d Phi \) were investigated, We also tested inverter operation of a de-biased Josephson logic gate composed of an rf SQUID and a de SQUID to realize logic circuit performance. Operation of the inverter has been successfully demonstrated although the operating temperature is low, around 10 K.