Kim Michelle Lewis

Kim Michelle Lewis
Rensselaer Polytechnic Institute | RPI · Department of Physics, Applied Physics, and Astronomy

PhD

About

37
Publications
4,851
Reads
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660
Citations
Citations since 2016
2 Research Items
360 Citations
201620172018201920202021202201020304050
201620172018201920202021202201020304050
201620172018201920202021202201020304050
201620172018201920202021202201020304050
Education
August 1998 - August 2003
University of Michigan
Field of study
  • Electrical Engineering
August 1998 - August 2004
University of Michigan
Field of study
  • Applied Physics
September 1994 - May 1998
Dillard University
Field of study
  • Physics

Publications

Publications (37)
Article
Atmospheric pressure chemical vapor deposition (APCVD) is employed for the synthesis of layered vanadium disulfide. By tuning several critical growth parameters, we achieve VS2 flakes with lateral dimension over 100 μm and thickness down to monolayer (~0.59 nm) and bilayer (~1.17 nm), larger and thinner than those previously reported in the literat...
Article
We report rectification from porphyrin molecules ligated to an iron atom. Current-voltage (IV) curves were measured from the molecules using a conductive atomic force microscope (AFM). Molecules were deposited on a substrate from template-stripped gold from 1 μM iron porphyrin solution by either a drop-dry or 60 s deposition method. The measured IV...
Article
Full-text available
We test a particular theory of dark matter in which dark matter axions form ring "caustics" in the plane of the Milky Way against actual observations of Milky Way stars. According to this theory, cold, collisionless dark matter particles with angular momentum flow in and out of the Milky Way on sheets. These flows form caustic rings (at the positio...
Article
We report bistability in current-voltage curves from di(PEP)PorZn in an electromigrated molecular junction. Bistability was observed at ±0.3 V at 300 K, but did not occur at 4 K. No bistability was identified at 300 K for another porphyrin molecule (di(Xyl)PorZn) where the phenyl-ethnyl-phenyl (PEP) side groups were replaced with a flexible para-xy...
Article
Full-text available
The knowledge on the influence of surface roughness and the electron–phonon (el–ph) interaction on electrical transport properties of nanoscale metal films is important from both fundamental and technological points of view. Here we report a study of the temperature dependent electron transport properties of nanoscale copper films by measuring temp...
Article
Full-text available
Electron phonon (el-ph) coupling is a fundamental quantity that controls the electron transport through a conductor. We experimentally determined the el-ph coupling strength of epitaxial copper (Cu) films ranging from 5 to 1000 nm thick using both ultra-fast, optical pump-probe reflectivity and temperature-dependent resistivity measurements. An enh...
Article
We report electron transport measurements from gold-zinc-porphyrin-gold molecular junctions formed in an electromigrated nanogap. Asymmetric current-voltage (I-V) behaviors about the zero bias voltage were observed at room temperature and 4.2 K. These observations are in contrast to measurements from a nanogap without any molecules, which are domin...
Conference Paper
As line width decreases below 15 nm, the diffusion barriers used in copper (Cu) technology in high performance integrated circuits significantly increase the overall resistivity of interconnects. In this work, we argue that the performance of pure W and Mo lines with line widths smaller than 15 nm could be better than that of Cu lines with barriers...
Chapter
Full-text available
Carbon nanotubes have remained at the center of nanotechnology research for the past two decades, and have been increasingly present in the areas of biology and biotechnology. While questions still remain about the toxicity of these materials, there is great interest in exploiting their unique properties to create innovative biotechnology applicati...
Article
Full-text available
We report room temperature measurements of current vs. voltage (I–V) from self-assembled Fe porphyrin [Fe(III) 5,15-di[4-(s-acetylthio)phenyl]-10,20-diphenyl porphine] molecular layers formed on annealed gold crystal facets on glass substrates. I–V curves were measured using an atomic force microscope with a conductive platinum tip. We observed a r...
Article
Quantized conductance measured from single tetraphenylporphyrin molecules with and without a central zinc(II) [Zn(II)] atom was measured using a molecular break junction (MBJ) method. From the conductance histo-grams we observed an additional 1.7 Å stretch for two-state conductance in a single Zn(II) tetraphenylporphyrin (ZnTPP) molecule as compare...
Article
We have developed a Layer-by-Layer (LbL) method for the fabrication of thin-film molecular multilayers on gold (111) electrodes. Copper(I) catalyzed azide-alkyne cycloaddition (CuAAC) coupling reactions were used for surface attachment and subsequent LbL deposition of porphyrin building blocks. The electrochemical and photophysical properties of th...
Article
As electronic devices become exceedingly small, incorporation of molecules as circuit elements is an attractive option due to their small size and the new functions that molecules can bring to the existing microelectronics. To realize such devices we have fabricated nanogaps of size 2-3 nm on gold wires and positioned porphyrin molecules in the gap...
Article
The authors report the fabrication of nanogaps formed by electromigration from gold wires of various widths (25–80 nm). This technique is a reliable and consistent method to create quality gaps without the need of very thin gold wires. The gaps are fabricated at room temperature and ambient atmosphere in contrast to the method of performing electro...
Article
We present a scalable and facile technique for noncovalent functionalization of graphene with 1-pyrenecarboxylic acid that exfoliates single-, few-, and multilayered graphene flakes into stable aqueous dispersions. The exfoliation mechanism is established using stringent control experiments and detailed characterization steps. Using the exfoliated...
Article
Full-text available
Conductance measurements were taken by forming single molecule junctions between a scanning tunneling microscope tip and a gold substrate. We observed the existence of a two-state conductance in porphyrin molecules ligating a zinc atom. Peaks in the conductance histograms showed molecules changed from a high conductance state to a low conductance s...
Article
Currently, transport properties through nanostructures are of considerable importance due to the increased demand for nanometer sized electronic devices. One of the main challenges is to create electrodes with nanometer sized separation, where nanoparticles or molecules can be incorporated. Electromigration has proved to be a consistent method for...
Article
Porphyrin molecules are a key platform for understanding molecular conductance. These molecules play an important role in biological processes, such as oxygen storage and transport, which researchers want to exploit for exotic applications, including multibit storage, memory elements, and photovoltaics. Recently, experiments investigated conductanc...
Article
Full-text available
A simple method to prepare gold tips for scanning tunneling microscopy has been introduced. In this method, electrochemical etching without a hazardous electrolyte was employed. The setup uses basic laboratory instrumentation to control the etching process. This avoids purchasing complicated, expensive, and dedicated equipment for tip preparation....
Article
Porphyrins have recently generated great interest as a potential ``electronic material'' for use in functions such as sensing (i.e.-carbon monoxide), biomolecular and medical physics applications (i.e. antiviral agents) and for computer memory capability. Fundamental to the latter of these three and to the realization of molecular based electronic...
Article
We studied a bilayer system consisting of a two-dimensional electron gas in a GaAs∕AlGaAs heterostructure and a thin superconducting Al film. Drag measurements were made by passing current through the two-dimensional electron gas layer and measuring the voltage induced in the superconducting layer. Unexplained peaks in drag voltage near the transit...
Article
We studied a bilayer system consisting of a two-dimensional electron gas in a GaAs/AlGaAs heterostructure and a thin superconducting Al film. Our goal was to probe the coupling between the electrons and the thermally excited vortices present near the superconducting transition temperature. Drag measurements were made by passing current through the...
Article
Thiol-coated Au nanoparticle films have recently generated interest as a sensing material for vapor detection. We have synthesized Au nanoparticles of 2-4.5 nm diameters with various thiol coatings, and deposited them on interdigitated electrodes with different electrode spacings ranging from 0.1 mum to 1 mum. All the films we have studied exhibit...
Article
We studied coupling between a thin Al film and a two dimensional electron gas (2DEG) via two methods. The structure consisted of a thin Al film evaporated on a GaAs/AlGaAs heterostructure containing a 2DEG with separate electrical contacts for each layer. The Al film was 25 nm thick and had a normal state sheet resistance of 600 omega. The 2DEG had...
Article
As electronic devices become extremely small, the charging energy associated by putting a single electron on the device can change its transport properties. In the extreme limit, when the energy is much larger than the energies associated with thermal and quantum fluctuations, the motion of charges is restricted. A new kind of electronics has emerg...
Conference Paper
We present a nanofabrication technique to make electrodes with a separation below 10 nm. This technique takes advantage of the atomic precision of molecular beam epitaxial growth. The key step in the fabrication is the formation of a nanotemplate by selective etching on the cleaved surface of a GaAs/AlGaAs heterostructure. Electrodes with a spacing...
Article
We study electrical transport through self-assembled Au nanoparticle clusters which can be viewed as a new model system to study hopping transport. The physics of such systems is governed by two parameters: the charging energy and tunnel coupling between the particles. The charging energy is determined by the size of the nanoparticles. When the dia...
Article
Full-text available
Operation and noise analysis of a recently proposed noise-matching device, called a charge transformer, are presented. The charge transformer consists of N identical capacitors and 3N+13N+1 switches that enable the capacitors to be connected either in series or in parallel. The device is operated by switching back and forth between these two config...
Article
We explore the possibility of using low-dimensional GaAs/AlGaAs heterostructures as phonon detectors. We have fabricated 1 mm long and 0.8 mum wide meandering wires, which can be used as tunable phonon detectors in magnetic field. The energy scale in such a detector is given by the cyclotron energy, which can be varied by changing the magnetic fiel...
Article
We ask the question: how does the discreteness of electron charge affect the operation of a switch? More precisely: When a switch opens, how do the discrete electron charges rearrange themselves on the two sides of the switch? If we could sense such a rearrangement, we could demonstrate a new explicit manifestation of the discrete charge. We believ...
Article
We studied the coupling between vortices in a superconducting film and electrons in a two-dimensional electron gas (2DEG). We measured structures consisting of a thin Al film evaporated on a GaAs/AlGaAs heterostructure containing a 2DEG patterned in a 1mmx4mum Hall bar structure. This structure allowed us to vary the carrier density of the 2DEG in...
Article
Thiol-coated Au nanoparticles have recently been used as sensing films in vapor sensing chemiresistors. To study electrical transport we have synthesized 5 nm diameter Au nanoparticles coated by conjugated thiol which is chemically stable and has relatively low-resistance. We have measured temperature dependent current-voltage characteristics throu...
Article
We present a new device, called a charge transformer, which can be used to enhance noise performance of single electron transistor (SET) amplifiers when placed between a low capacitance SET and a high capacitance device under test. The function of a charge transformer is analogous to that of a flux transformer commonly used with superconducting qua...
Article
Full-text available
A device, called a charge transformer, is proposed for noise matching single-electron transistor amplifiers to high-capacitance devices. The operation principle is demonstrated on a prototype charge transformer with four capacitors made using a GaAs/AlGaAs heterostructure with a two-dimensional electron gas. © 2002 American Institute of Physics. Pe...
Article
Full-text available
We analyze the potential performance of quantum point contact (QPC) devices in charge detection applications. For the standard QPC structure we show that the charge sensitivity is strongly dependent on gate geometry and can be close to the quantum limit, and that the gain parameter is less than one under bias conditions where the charge sensitivity...
Article
We propose a novel quantum point contact (QPC) device with high gain and a charge sensitivity close to that of single electron transistors. The device can be realized using high quality GaAs/AlGaAs with a two-dimensional electron gas and standard nanofabrication techniques. The device consists of two split gates for defining the QPC and a third gat...

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