title: Generation of constant-amplitude radio-frequency sweeps at a tunnel junction for spin resonance STM.
abstract: We describe the measurement and successful compensation of the radio-frequency transfer function of a scanning tunneling microscope over a wide frequency range (15.5-35.5 GHz) and with high dynamic range (>50 dB). The precise compensation of cabling resonances and attenuations is critical for the production of constant-voltage frequency sweeps for electric-field driven electron spin resonance (ESR) experiments. We also demonstrate that a well-calibrated tunnel junction voltage is necessary to avoid spurious ESR peaks that can arise due to a non-flat transfer function.
authors.affiliation: IBM Research Division, Almaden Research Center, 650 Harry Road, San Jose, California 95120, USA.
authors.forename: William
authors.initials: W
authors.lastname: Paul
authors.affiliation: IBM Research Division, Almaden Research Center, 650 Harry Road, San Jose, California 95120, USA.
authors.forename: Susanne
authors.initials: S
authors.lastname: Baumann
authors.affiliation: IBM Research Division, Almaden Research Center, 650 Harry Road, San Jose, California 95120, USA.
authors.forename: Christopher P
authors.initials: CP
authors.lastname: Lutz
authors.affiliation: IBM Research Division, Almaden Research Center, 650 Harry Road, San Jose, California 95120, USA.
authors.forename: Andreas J
authors.initials: AJ
authors.lastname: Heinrich