Low-temperature scanning-tunneling microscope for luminescence measurements in high magnetic fields

Abstract

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Simple and efficient scanning tunneling luminescence detection at low-temperature

“…The ability to do polarized measurements without the need to install in situ polarization filters and rotation mounts is a further advantage of the current and other designs [11][12][13][14] over designs that employ an in situ optical fiber to collect the luminescence. 8,15,16 …”

“…Since the processes of luminescence emission are governed by the position and size of the STM tip, STL has the potential to study the optical properties of a surface on the atomic scale. Several STL-modes of operation have been reported in literature ranging from relatively straight forward intensity measurements 7,8 to spectral and spatial resolved photon mapping. 6,9 In the latter technique luminescence spectra are collected during scanning, resulting in a map of spectra which can be directly linked to the topographic information.…”

Versatile optical access to the tunnel gap in a low-temperature scanning tunneling microscope

“…Experiments in UHV at liquid He temperature provide superior stability and reproducibility with respect to STM performance and sample characterization. Low temperature setups have thus been realized earlier, e.g., by separate cooling of an externally adjusted lens to liquid nitrogen temperature, 11,16 collecting by optical fibers, 17 or the use of a conductive transparent tip attached to a fiber. 18 Maintaining the instrument constantly at liquid He temperature while using free propagating beams requires a new design which restricts thermal input into the STM.…”

Scanning tunneling spectroscopy on organic semiconductors: Experiment and model

“…In the second setup, 28 the measurements were done in a He atmosphere. Here we used Pt tips that were electrochemically etched 29 from 0.15-nm polycrystalline wire.…”