Using a scanning tunneling microscope, we demonstrated that a single copper-oxide plane can form a stable layer at the superconductor's surface. This plane behaves differently when exposed at the surface than when buried inside the crystal, offering additional insight into the behavior of high-temperature superconductors.
Published in Physical Review Letters:
Atomic Scale Imaging and Spectroscopy of a CuO2 plane at the Surface of a High-Tc Superconductor, S. Misra, D. J. Hornbaker, S. Oh, T. DiLuccio, J. N. Eckstein, and Ali Yazdani, Physical Review Letters 89, 87002 (2002). (Letter)