Peter J. A. Nordlander, Ph.D. - US grants

Theoretical Description of Charge Transfer Processes Near Metal Surfaces - This project has the goal of increasing our understanding of charge transfer phenomena between atoms or simple molecules and metal surfaces. In the first part, the complex scaling technique will be used to calculate the electron tunneling probabilities between excited atomic (or molecular) states and a model metal surface. In particular, the effects of impurity coadsorption and of lateral corrugation (model lattice structure) of the surface potential on these tunneling rates will be investigated. These transition rates will then be combined with a time-dependent scattering model to allow description of charge transfer processes in collisions taking place between an atom (or molecule) and a metal surface. Again, influences specific to real metallic surfaces will be included into the model. %%% The energy and lifetime of excited states of atoms and molecules at or near metal surfaces are controlling factors in many dynamical phenomena taking place near surfaces. For example, atoms bound to the surface can be desorbed through the action of light or energetic electrons if an electronically excited antibonding state has a long enough lifetime. This lifetime, however, depends strongly on the interaction between the atom and the metal surface. Similarly, the lifetime of excited states generated in atom-surface scattering help to determine the dispersion of the scattered beam. The goal of this project is to develop methods for evaluating the effect of a metal surface on a nearby atom, and to predict the ultimate result of this influence on the atom-surface scattering problem.

9314529 Norlander This three-year award supports U.S.-France cooperative research in materials theory between Peter A. J. Norlander at Rice University and Jean-Pierre Gauyacq and Dominique Teillet- Billy at the University of Paris, Orsay. The objective of their research is to increase understanding of the dynamics of negative ion formation in atom-surface scattering. This investigation will also include the study of effects such as the polarization of the atom and the image force near a metal surface. The U.S. investigator brings to this collaboration expertise in surface theory. This is complemented by the French investigators' expertise in atomic and molecular physics. The project also takes advantage of two complementary, yet contrasting methods for calculating energy shifts and the lifetimes of atomic states which were developed respectively by the U.S. and French groups. The development of a theory on how atoms/molecules interact with surfaces is fundamental to our understanding of processes such as catalysis and corrosion. This project will advance that theory and the field of surface physics in general. ***

9521444 Nordlander The objective of this research program is to increase the understanding of charge transfer phenomena between atoms and simple molecules, and metal surfaces. The Principal Investigator will develop and apply a dynamical many-body method, based on Green's functions, in which he calculates the charge transfer probabilities by solving a set of coupled integro-differential equations. The project includes an investigation of the influence of substrate temperature, particle velocity, atomic and molecular level degeneracy, substrate band width, and substrate density of states on charge transfer. The results of this project provide the theoretical background for an accurate description of charge-transfer processes in atom/molecule- surface collisions. This formalism helps to interpret specific experimental results and to relate microscopic properties of the surface to actual experimental data. %%% This project develops of theory of the scattering and colliding of atoms or molecules with metal surfaces. The main focus is on the transfer of charge between the surface and the colliding particle. Part of the project involves the development of the complex quantum theory that one needs to properly describe these collisions. The project includes an investigation of the influence of a variety of properties of both the substrate and the colliding particle on charge transfer. This formalism helps to interpret specific experimental results and to relate microscopic properties of the surface to actual experimental data. Such scattering events are a primary way to measure various physical properties of surfaces, the knowledge of which is necessary to develop new and better materials. ***

9911858
Nordlander

This award supports a three year collaborative research project between Professor Peter Nordlander of Rice University in Texas and Professor Mineo Kimura of Yamaguchi University in Japan. The researchers will be undertaking a study of ion molecule/surface scattering with emphasis on orientation effects. The understanding of inelastic effects in the scattering of ions against surfaces represent a challenging interdisciplinary problem of importance both in scientific and technological applications. The objective of the research is to increase the understanding of the collision dynamics of ions/atoms/molecules with surfaces in the energy range 100 eV to 10 keV. This represents a complex problem where it is essential to employ an accurate description of the scattered molecules, the microscopic properties of surfaces, the physics and chemistry of chemisorption as well as the physics of collisions.

The project brings together the efforts of two laboratories that have complementary expertise and research capabilities. The U.S. researchers' expertise is in the area of surface physics and molecular chemistry and the Japanese have expertise in ion-atom scattering in the gas phase. The results of the research will be of considerable importance for a large number of experimental groups that use ion-surface scattering as an experimental probe of surface electronic and geometric structure. The theory developed can directly be used to interpret experimental data and to deduce microscopic information of surfaces. Also, these scattering phenomena have applications in fusion plasma interaction with the walls of confinement, surface property measurement technology, and the microelectronic industry. The project advances international human resources through the participation of a postdoc. Through the exchange of ideas and technology, this project will broaden our base of basic knowledge and promote international understanding and cooperation. Results of the research will be published in scientific journals and also on their Web site (http://juktan.rice.edu).
9911858
Nordlander

This award supports a three year collaborative research project between Professor Peter Nordlander of Rice University in Texas and Professor Mineo Kimura of Yamaguchi University in Japan. The researchers will be undertaking a study of ion molecule/surface scattering with emphasis on orientation effects. The understanding of inelastic effects in the scattering of ions against surfaces represent a challenging interdisciplinary problem of importance both in scientific and technological applications. The objective of the research is to increase the understanding of the collision dynamics of ions/atoms/molecules with surfaces in the energy range 100 eV to 10 keV. This represents a complex problem where it is essential to employ an accurate description of the scattered molecules, the microscopic properties of surfaces, the physics and chemistry of chemisorption as well as the physics of collisions.

The project brings together the efforts of two laboratories that have complementary expertise and research capabilities. The U.S. researchers' expertise is in the area of surface physics and molecular chemistry and the Japanese have expertise in ion-atom scattering in the gas phase. The results of the research will be of considerable importance for a large number of experimental groups that use ion-surface scattering as an experimental probe of surface electronic and geometric structure. The theory developed can directly be used to interpret experimental data and to deduce microscopic information of surfaces. Also, these scattering phenomena have applications in fusion plasma interaction with the walls of confinement, surface property measurement technology, and the microelectronic industry. The project advances international human resources through the participation of a postdoc. Through the exchange of ideas and technology, this project will broaden our base of basic knowledge and promote international understanding and cooperation. Results of the research will be published in scientific journals and also on their Web site (http://juktan.rice.edu).

Abstract

The objective of this research is the development of a new type of a scanning local probe microscope capable of obtaining chemical information with nanoscale resolution and to utilize this microscope in a wide range of applications pursued by different research groups at Rice University. The microscope will consist of a metallodielectric nanoparticle mounted or integrated as an Atomic Force Microscope tip (AFM) tip. The nanoparticle will be designed to have plasmon resonant response in the infrared region of the spectrum (2.7 -10 microns in wavelength; 1000-3600 cm-1). The strong electromagnetic field enhancements associated with the excitations of plasmons in the probe tip will dramatically enhance the cross sections for infrared excitation of dipole active vibrational modes in the tip-sample junction

This project will result in a new and unique nanoscale spectroscopic tool that will be useful across a very broad range of technical applications, such as fundamental nanoscale studies in the physical and chemical sciences, a valuable new imaging probe in the life sciences, and a unique, breakthrough sensor technology for environmental analysis and detection of trace chemical species. The highly collaborative multidisciplinary instrument development team consists of researchers in the departments of Electrical and Computer Engineering, Chemistry, Physics, and Bioengineering. Two courses will be developed during this project addressing the theoretical and experimental aspects of nanoscale instrument component design and fabrication. A large number of users for this instrument have been identified within the Rice science and enginee

Proposal #: CNS 08-21727
PI(s): Mellor-Crummey, John
Clementi, Cecilia; Nakhleh, Luay; Nordlander, Peter A.; Tezduyar, Tayfun E..
Institution: Rice University
Houston, TX 80309-0572
Title: MRI/Acq.: Acq. of Cyberinfrastructure for Computational Research (CCR)
Project Proposed:
This project, acquiring instrumentation and operating a computational cluster for research (CCR), enables code development, medium scale computation, preparation of scalable codes for execution on national-scale resources, post-processing and visualization of results from remote supercomputers, and research training. Projects range from development of enabling technologies, such as programming models and performance analysis tools for parallel systems, to computational science and engineering research that includes techniques for automated verification of complex hardware and software designs, data mining of multiple whole genomes, studying large-scale ecological dynamics, determining the properties of nanophotonic structures through simulation, simulating protein dynamics to study flexibility and function, modeling transport properties in biophysical systems, and understanding fluid structure interactions in physiological systems and engineering designs. The increase in the number of CPU hours available for shared research computing contributes to support the explosive growth of computational research. Hence, more tightly coupled computing can be supported at a higher scale; a centralized computing facility can be scheduled for higher utilization; a single system can be operated and administered (rather than collections of cluster for individual research groups, and may effectively on-ramp national resources. Operating this modest-size computational cluster locally complements the TeraGrid and accelerates research. In particular, higher bandwidth and lower latency to the desktop from a local system better supports code development using interactive tools with graphical user interfaces (e.g., for debugging, performance, and scalability analysis, and data visualization) while preparing codes for execution on national-scale resources. Indeed, computation is an indispensable tool for scientific inquiry and complements traditional approaches of theory and experimentation.

Broader Impacts:
CCR enhances the graduate research and training of hundreds of students and post-doctoral fellows in science and engineering. It provides educational experience for undergraduate and graduate students through its use in courses that integrate high performance computing and computational problem solving. Furthermore, a boot-camp will familiarize students with high performance computing and teach computational problem solving skills. The instrument also contributes to recruiting and serves as an educational tool in the Alliance for the Graduate Education and the Professoriate (AGEP), a successful program in attracting members from underrepresented groups into higher education, thus broadening their educational experience.

Research Objectives and Approaches: The objective of this research is to develop an integrated instrument for the fabrication and characterization of plasmonic nanostructures and nanodevices. The approach combines a scanning electron microscope with imaging, localized etching and deposition, and lithography capabilities, with optical spectroscopies, cathodoluminescence, and electrical characterization.

Intellectual Merit:

The proposed platform integrates structural, optical, and electrical characterization to a level substantially above any current commercial or custom-built system. This system will allow the development of active plasmon-based structures and devices, with direct fabrication and characterization. The developmental challenge in this project is the integration of the variety of techniques into one platform and the leveraging of this combined capability to achieve new strategies for developing active plasmonic systems.

Broader Impact:

The availability of this platform will greatly enhance current experimental capabilities in plasmonics, nanoscale photonics and optoelectronics, advancing our understanding of the physical principles upon which their behavior is based. This will enable new applications of plasmonic systems currently limited by joint challenges in the fabrication and characterization of active plasmonic nanostructures.

Rice currently supports an IGERT program in Nanophotonics, a professional master?s program in Nanoscale Physics and an undergraduate REU program ?Conjunto? aimed at underrepresented minority students. The availability of the proposed instrument would provide an unmatched opportunity for all students to participate in research in nanophotonics. The cathodoluminescence capability is not available even as a standalone instrument in the Houston area. This experimental system will be welcomed by the growing nanophotonics research community in southeast Texas.

With this award from the Major Research Instrumentation (MRI) program and support from the Chemistry Research Instrumentation (CRIF) program, Professor Isabell Thommann from the William Marsh Rice University will acquire parts to asssemble a femtosecond time-resolved nanophotonic scanning probe microscope. This will make it possible to study nanostructured materials synthesized for energy and sustainability applications with unprecedented spatial and temporal resolution. These measurements will allow probing the chemical and physical properties of the materials to help understand energy flow and charge carrier dynamics in hybrid nanostructured materials. This will help to address challenges in the production of large scale applications of these materials. The acquisition will be a multiuser instrument used by researchers at the university and also for new collaborations in the Houston area, and nationally. It will strengthen the outreach efforts at the university to high school teachers and students.

The award is aimed at enhancing research and education at all levels, especially in areas such as (a) studying charge separation kinetics in all-conjugated block copolymer thin films; (b) investigating carrier dynamics in two-dimensional materials and devices for energy; (c) using time-resolved photoluminescence as a probe of hot electron dynamics; (d) studying hot electron dynamics in plasmonic antennas; (e) carrying out spatiotemporal investigations of photocatalytic virus inactivation; (f) studying photocatalytic water splitting on nanostructured cobalt oxide by time-resolved tip-enhanced Raman scattering; (g) investigating photocatalytic water splitting on plasmonic photoelectrodes.

The identification of small molecules in our atmosphere, water supply, and exhaled breath or body fluids, is an extremely important capability with applications ranging from identification of dangerous environmental toxins to early-stage disease detection. The methods that are currently available to perform this type of chemical identification, however, require large, expensive and sensitive instruments, are available only in laboratory settings, and are based on decades-old technologies. The work enabled by this research grant aims to combine two recent research advances to develop a new approach for identifying small molecules. This work could ultimately provide chemical identification capabilities in ultracompact geometries that could be used in a variety of non-laboratory settings. The ability to rapidly detect and accurately identify molecules in the clinic or in the field has wide-ranging has applications in areas ranging from agriculture, pharmaceuticals, food quality control, and medical screening, including brain function. This approach could ultimately be used for identifying a plurality of molecules at a fully integrated, chip-based level of detection compatible, ultimately, with cloud-based processing and smart-phone-based data acquisition. The cross-cutting, multidisciplinary concepts central to this proposal provide a broad opportunity for student education at the high school, undergraduate, and graduate student level.
Technical Description:
The goal of this proposal is to develop highly compact infrared spectroscopic capabilities based on narrowband nanoantenna-diodes for near-infrared molecular spectroscopy. Two independent research advances in nanophotonics were recently pioneered which, when combined, are ideally suited to address this goal. They are: (1) the demonstration of optically active nanoantenna-diodes, where carriers are generated by the decay of photoexcited surface plasmons in resonant metallic nanoantennas, then injected into the conduction band of the adjacent semiconductor, and (2) the development of infrared nanoantennas tuned to the resonant vibration frequencies of specific chemical functional groups. By merging these two concepts, narrowband, infrared active nanoantenna-diodes for the spectroscopic identification of small molecules with direct electrical readout will be created. Efforts will focus on the development of nanoantenna-diodes with enhanced responsivities and quantum efficiencies, through the implementation of gain, and on lineshape control of the nanoantenna-diode spectral response, to ultimately resolve molecular spectral lines in the near-infrared region of the spectrum. This approach would ultimately eliminate the need for near-infrared photodetectors based on costly materials, along with the bulky dispersive optics and large optical path lengths required in conventional infrared spectroscopy for wavelength discrimination.