Modifying electronic properties of interfaces in high-T-c superconductors by doping

The superconducting and normal-conducting transport properties of interface s play an important role for numerous applications of high-T-c superconduct ors. For basic reasons, the physics of interfaces in high-T-c superconducto rs is considerably richer and more complex than that of interfaces in the c onventional low-T-c superconductors. Besides the unconventional order param eter symmetry of the high-T-c cuprates, as described previously, another di fference originates from the possibility of significant band-bending in the high-T-c superconductors, leading to the formation of space-charge layers with modified electronic properties near the interfaces. In analogy with se miconductors, the space-charge layers in the high-T-c cuprates can be alter ed by doping the material or by the application of electrostatic fields, en abling a controlled modification of the transport properties of the interfa ces. (C) 1999 Elsevier Science B.V. All rights reserved.