Point Contact Studies of High TcSuperconductors

Point Contact Transducer of Waveguiding Structure for High-frequency Operation

Time-of-flight measurements with point-like contact transducers have successfully been applied for the detection of anisotropy, and for in situ measurements of film thickness and temperature. The operation frequency range of the pin transducers made so far was, however, restricted at several hundreds of kHz. This paper presents a new type of Hertzian-contact transducer of waveguiding structure ...

Point of Contact

Quantum point contact microscopy.

We introduce quantum point contact microscopy (QPCM) as a novel method for surface characterization, where the conductance through a quantum point contact formed by a metal atom between the tip of a scanning tunneling microscope and the surface is mapped across the surface. Application of QPCM to copper and gold (111) shows reproducibly atomic resolution, on gold (111) the alternating atomic st...

Point-contact Spectroscopy of Superconductors

Resonant multilead point-contact tunneling

We analyze a model of resonant point-contact tunneling between multiple Luttinger-liquid leads. The model is a variant of the multichannel Kondo model and can be related to the quantum Brownian motion of a particle on lattices with p flux through each plaquette ~in the three-lead case, it is a honeycomb lattice with p flux!. By comparing the perturbative and instanton gas expansions, we find a ...