title: Design and construction of a point-contact spectroscopy rig with lateral scanning capability.
abstract: The design and realization of a cryogenic rig for point-contact spectroscopy measurements in the needle-anvil configuration is presented. Thanks to the use of two piezoelectric nano-positioners, the tip can move along the vertical (z) and horizontal (x) direction and thus the rig is suitable to probe different regions of a sample in situ. Moreover, it can also form double point-contacts on different facets of a single crystal for achieving, e.g., an interferometer configuration for phase-sensitive measurements. For the later purpose, the sample holder can also host a Helmholtz coil for applying a small transverse magnetic field to the junction. A semi-rigid coaxial cable can be easily added for studying the behavior of Josephson junctions under microwave irradiation. The rig can be detached from the probe and thus used with different cryostats. The performance of this new probe has been tested in a Quantum Design PPMS system by conducting point-contact Andreev reflection measurements on Nb thin films over large areas as a function of temperature and magnetic field.
authors.affiliation: Dipartimento di Scienza Applicata e Tecnologia, Politecnico di Torino, Torino 10129, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Tortello
authors.affiliation: Department of Physics and Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
authors.forename: W K
authors.initials: WK
authors.lastname: Park
authors.affiliation: Department of Physics and Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
authors.forename: C O
authors.initials: CO
authors.lastname: Ascencio
authors.affiliation: Department of Physics and Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
authors.forename: P
authors.initials: P
authors.lastname: Saraf
authors.affiliation: Department of Physics and Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
authors.forename: L H
authors.initials: LH
authors.lastname: Greene