News & Events

Image of the Month
Posted Date: March 1, 2011
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(a)–(c) Intensity plots of G(V)/GN as a function of temperature and applied bias for three different films (upper panels), and the resistance vs temperature (R-T) in the same temperature range (lower panels); vertical dotted lines in the upper panels correspond to Tc. Insets of panels (a),(b) and left inset of panel (c) show representative tunneling spectra in the superconducting state (blue), in the pseudogap state (green) and above the pseudogap temperature (red). The right inset of panel (c) shows the AA background subtracted spectra at 2.65 K. [right inset of Fig. 2(c)] clearly reveals the presence of broadened coherence peaks around 2 mV confirming the superconducting origin of the pseudogap feature. In addition, the individual line scans [23], reveal that the superconducting state becomes progressively inhomogeneous as the disorder is increased [11].

Microscope:
Homebuilt STM

Controls:
RHK SPM 100

Contributors:
M. Mondal, A. Kamlapure, M. Chand, G. Saraswat, S. Kumar, J. Jesudasan, L. Benfatto, V. Tripathi, and P. Raychaudhuri – Tata Institute of Fundamental Research and Sapienza University

Reference:
Phys. Rev. Lett. 106, 047001 (2011)

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Press Releases
Posted Date: February 15, 2011

The US Air Force has awarded RHK Technology, Inc. Phase II STTR funding to develop ground-breaking Nano-analytical instruments crucial for National Security and American research and industrial competitiveness.

RHK is collaborating with Dr. Lukas Novotny and the University of Rochester Nano-Optics group. They are combining their expertise to develop and commercialize a Nano-Spectroscopy platform to perform chemically-specific imaging with high spatial resolution at a level far surpassing the best products found in the market today. The RHK-Novotny team successfully demonstrated their novel techniques in Phase 1 and is now the only group awarded Phase II funding.

Adam Kollin, RHK President, said, “Identifying both the ‘where’ and the ‘what’ of unknown compounds – and doing so non-destructively – delivers huge advantages in materials science, nanotech, and catalysis. We call it Hyperspectral Imaging, or chemical fingerprinting at the nano-scale.” For Military and Security applications, such an instrument could screen for and reverse engineer high energy density materials, radar absorbing materials, biologically active nano-systems, and nuclear nanomaterials.

The Nano-Spectroscopy Platform is the first to enable a non-specialist or specialist to produce and analyze high quality spectroscopic data correlated with nanometer scale topographic images in real time. It is also the first to enable simultaneous use of all contact and non-contact AFM and STM imaging modes with spectroscopic tasks such as confocal and tip-enhanced fluorescence, extinction, Raman scattering and other nonlinear scattering.

The market demand and commercial potential for this capability are broad, multi-faceted, and growing rapidly. In Phase II, instrument capabilities will be further advanced and packaged as a Platform at an initial stage of commercial productization. Full standardization for manufacturing and formal release will commence in Phase III.

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Image of the Month
Posted Date: February 1, 2011
institution

Porphyrin derivatives are promising candidates for the generation of functional molecular architectures on surfaces. The unambiguous identification of individual porphyrin species is a prerequisite in this regard. We investigated a layer of intermixed tetraphenylporphyrins (TPP), namely 2HTPP, FeTPP and CoTPP at room temperature. Voltage-dependent STM imaging was successfully applied to discriminate the very similar porphyrins. The characteristic appearance of CoTPP at low negative voltages (>-0.4 V) can be traced back to a specific interaction of the Co dz2 orbital with the underlying Ag substrate. The dumbbell appearance observed for FeTPP over a wide bias range and for CoTPP at lower negative voltages (<-0.4 V) is in line with the well known saddle shape of the porphyrin macrocycle in the adsorbed state.

Microscope:
UHV300 VT

Controls:
RHK SPM 100

Contributors:
F. Buchner, K.-G. Warnick, T. Wölfle, A. Görling, H.-P. Steinrück, W. Hieringer and H. Marbach – Universitat Erlangen-Nurnberg

Reference:
J. Phys. Chem. C 2009, 113, 16450–16457

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Image of the Month
Posted Date: January 1, 2011
institution

Raw images showing the friction signal in the left-to-right sliding direction. Upper row: 4-layer graphene; lower row: bulk graphite; right column: Low-pass filtered images of the friction measurements showing the periodicity of the lattice. Black dots represent the periodic sites of the friction force signal. The scale bars correspond to 0.5 nm.

Microscope:
UHV350

Controls:
RHK SPM 100

Contributors:
Q. Li and R.W. Carpick, University of Pennsylvania

Reference:
Science 328, 76 (2010) DOI: 10.1126/science.1184167

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