Study on the relationships between the single electron tunneling currents and tunneling voltages of YBa2Cu3O7-δ high temperature superconducting thin films by a Scanning Tunneling Microscope( STM)

Abstract

In this thesis, we mainly discuss the relationships between the single electron tunneling currents and tunneling voltages of YBCO high temperature superconducting thin films with various oxygen contents by a scanning tunneling microscope(STM). YBCO films were fabricated on several substrates by pulse laser deposition(PLD) method. Their oxygen contents were controlled with a homemade system. The tunneling currents I and tunneling voltages V were measured with the STM. The tunneling currents were then differentiated with respect to the voltages and the resulting dI/dV-V curves were used to calculate the superconducting energy gaps.