Scientists at CEMES have recently pushed to the limits their new ScientaOmicron low-temperature tunneling microscope (LT-UHV 4-STM) installed in October 2014 at Pico-Lab. This unique instrument is equipped with 4 STM scanners capable of operating on the same surface and in parallel. On the surface Au (111) and at 4.3 K, CEMES researchers managed to reproduce for the first time a series of experiments now performed on the most stable single tip LT-UHV STM around the world. The STM images produced by the 4 scanners on the same surface (independently or in parallel) have a DZ stability better than 2 pm per STM scanner. The minimum inter STM tip apex distance is a few tens of nanometers and is measured using a high resolution UHV SEM equipping this instrument as well. With this stability, single atom manipulations were carried while recording the famous corresponding manipulation signals to recover the pushing, pulling and sliding atom manipulation modes per STM tip. Electrical contact experiments on a single atom were also performed to record the current-voltage characteristic (I-V) of a single Au atom exactly in contact and demonstrating a quantum of conductance. No average over multiple I-V characteristics was required for these measurements. Floating surface two-points conductance measurements were also conducted on the Au(111) surface using a lock-in technique to locate the Au(111) surface states near the Fermi level.
The results of the CEMES scientists show how this new instrument is exactly 4 times the most accurate tunneling microscope in the world. Such equipment will now be used to measure the electronic conductance of a single atomic wire constructed atom by atom in planar configuration and also the motive power of a molecule motor about 1 nm in rotor diameter. The future spring 2017 international molecule car race will take place on this instrument.
- Une vue de dessus de la tête LT-UHV 4-STM utilisée dans ce travail et une image STM pseudo 3D (5.12 nm x 5.12 nm) de la lettre C construite atome par atome avec 6 ad- atome d’Au sur une Au (111) reconstruite. Les manipulations d’atomes et les images STM ont été obtenues sur le scanner 3 de cette machine pour I = 50 pA, V = 500 mV avec ΔZ = 0,12 nm. La résistance de la jonction tunnel pour toutes les manipulations d’atome est de 333 KΩ.
- © CEMES-CNRS
Imaging, single atom contact and single atom manipulations at low temperature using the new ScientaOmicron LT-UHV-4 STM
Jianshu Yang1, Delphine Sordes1,2, Marek Kolmer3, David Martrou1 and Christian Joachim1,4a
1 Nanoscience Group & MANA Satellite, CEMES/CNRS, 29 rue Marvig, BP 94347, 31055 Toulouse Cedex, France
2 CEATech Midi-Pyrénées, Campus INSA, Bât. GM 135 avenue de Rangueil, 31400 Toulouse, France
3 Centre for Nanometer-Scale Science and Advanced Materials, NANOSAM, Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, Lojasiewicza 11, 30-348 Krakow, Poland
4 International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
Eur. Phys. J. Appl. Phys. (2016) 73 : 10702
Dr Christian Joachim : christian.joachim chez cemes.fr