Chandralekha Singh - US grants

This project investigates the electronic and optical properties of conducting polymers using quantum Monte Carlo simulation techniques. The large nonlinear optical response and ultrafast response at the sub-picosecond level make certain polymer structures excellent candidates for fast switching and memory devices. The approach is to study the influence of Coulomb interactions, quantum lattice fluctuations, and disorder on and localization properties. The results are expected to resolve discrepancies in the measured values of nonlinear optical susceptibility by various experimental groups, particularly the puzzling presence of a two photon peak in the susceptibility spectrum. In addition, polyaniline derivatives, which exhibit large conductivities comparable to the native form, despite the broken structural symmetry will be modeled. Simulations will be carried out as a function of the strength of Coulomb interaction, disorder, ionic mass and dopant concentration.
%%%
This is a research enhancement grant made under the Professional Opportunities for Women in Research and Education (POWRE) program. The research will contribute basic materials science knowledge relevant to the understanding and utilization of polymers in electronic/photonic applications. The interdisciplinary project involves collaborations among theory and experiment across physics and chemistry, and also places emphasis on the integration of research and education by incorporating graduate student participation into research related to classroom activities. The project is co-supported by the Division of Materials Research, and the MPS OMA(Office of Multidisciplinary Activities).
***

Physics (13) A "Physics Exploration Center" (PEC) to supplement lecture-oriented teaching in large introductory physics courses has been designed. At the PEC, physics lecture demonstrations are turned into fun activities that are integrated with the introductory courses. The PEC has been tried on a small scale, and this project is expanding it so that it can serve large numbers of students. The central objective of PEC is to provide students an opportunity for hands-on, demonstration-based homework problems. The PEC experience is different from that of a traditional laboratory, and is meant to be more conceptual and open-ended. The primary purpose is to help students with conceptual understanding of the lecture material, challenge their preconceptions by providing contradictory experiences, and introduce them to scientific method. PEC activities can be particularly beneficial for the intellectual development of underprepared students.

To better prepare future scientists and engineers for the demands of a high-tech workplace, development and assessment of guided tutorials for advanced undergraduate quantum mechanics courses will be undertaken. Although tutorials at the level of modern physics have been developed and have proved effective, there are presently no similar tools available for advanced undergraduate quantum mechanics courses. The tutorials will actively engage students in the learning of quantum physics. They will attempt to bridge the gap between the abstract quantitative formalism of quantum mechanics and the qualitative understanding necessary to explain and predict new phenomena. Based upon research in physics education, their development will be guided by a careful attention to cognitive issues. The tutorials will supplement lectures and standard homework assignments. Some tutorials will include design and adaptation of computer-based visualization tools to help students build physical intuition about quantum processes.

In order to promote widespread use of these tutorials, information about the project will be disseminated through presentations at the American Association of Physics Teachers meetings, dedicated workshops and seminars in physics departments. After the modules have been thoroughly evaluated at several institutions and refined, the ultimate goal is to publish the tutorials as a quantum mechanics workbook.

Intellectual Merit: The project is developing and assessing a set of twenty interactive video tutorial-based problems to help introductory physics students in calculus- and algebra-based courses learn effective problem-solving techniques. Effective problem solving begins with a qualitative analysis, followed by decision making, implementation, assessment, and reflection phases. Most introductory students do not acquire these techniques automatically and need help with them. Students are learning problem solving skills using concrete examples in an interactive environment. They are required to solve sub-problems (research-guided multiple-choice questions) to show their level of understanding at every stage of problem solving. The alternative choices in the multiple-choice questions elicit difficulties students commonly have with relevant concepts.

Broader Impact: The self-paced nature of the web-accessible tutorials and the problem-solving approach illustrated in them are flexible and adaptable enough to meet the needs of a diverse variety of students including those who are at risk and need extra help. Underrepresented minorities, students with learning disabilities and women who are typically more hesitant or intimidated about asking for help from instructors particularly may benefit from these tutorials. The tutorials can be used both as aids to problem solving in homework assignments and as a self-study tool by students. They can be an asset to the graduate teaching assistants and faculty as well as high-school teachers and students. A longer term goal is to integrate the videos with an introductory physics sequence and textbook.

Assessment of the project comes from in-class and out-of-class control studies, which complement each other. The out-of-class study compares the performance of "matched" students using tutorials with the video, audio and text options with each other and against those who receive identical content from non-tutorial means. Evidence for the development of the meta-cognitive ability can be tracked by analyzing students' think-aloud protocol during the interviews. The in-class study compares the performance of students who use tutorials with those who do not use them in similar classes in the natural classroom setting. The evaluation of the project is useful for educators who are interested in developing distance education tools.

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). This award supports the continued development, assessment, and dissemination of Quantum Interactive Learning Tutorials (QuILT) for advanced undergraduate courses. QuILTs are based upon a field-tested cognitive apprenticeship model of learning and emphasize modeling, coaching, and scaffolding. The following features of the QuILTs make them particularly suited for the challenging task of teaching quantum physics: (1) They are based upon research in physics education and pay particular attention to cognitive issues. (2) They consistently keep students actively engaged in the learning process by asking them to predict what should happen in a particular situation and then providing appropriate feedback. (3) They employ visualization tools to help students build physical intuition about quantum processes. (4) They attempt to bridge the gap between the abstract quantitative formalism of quantum mechanics and the qualitative understanding necessary to explain and predict diverse physical phenomena. (5) They are based on systematic investigations of difficulties students have in learning various concepts in quantum physics. (6) They can be used in class by the instructors once or twice a week as supplements to lectures or outside of the class as homework or as self-study tool by students. (7) They consist of self-sufficient modular units that can be used in any order that is convenient. To aid instructors, the various concept-based and problem-based QuILT modules will be keyed with most of the common textbooks. However, every effort will be made to ensure that the different modules fit together as a coherent whole and help students organize their knowledge in a hierarchical fashion.

This award supports the development, assessment, and dissemination of resource material for "Peer Instruction" in undergraduate Quantum Mechanics courses, ranging from the sophomore level to the senior llevel. The resource material to be developed includes "ConcepTests" for formative assessment, standardized assessment tools for summative assessment and material for Just-In-Time Teaching (JITT) for modern physics and quantum mechanics courses. This pedagogical method keeps students actively engaged in the learning process and it is hoped that this material will be widely adapted. The research-based material will be developed using findings of student misconceptions and difficulties in learning quantum mechanics. The assessment of the project will come from control studies comparing similar courses in Modern Physics and Quantum Mechanics in which Peer Instruction was employed vs. those in which this pedagogical method was not employed. Such studies will be conducted at several colleges and universities. It is intended that this project will help better prepare future scientists and engineers for an environment in which an understanding of quantum phenomena is rapidly increasing in importance.

This award provides support for a two-day workshop that would bring about 60 participants together to discuss the issues, challenges and opportunities in "Materials Education" and devise strategies for synergizing all stakeholders involved for further progress. "Materials Education" here refers to interdisciplinary education in the fields of materials science and materials engineering including physics, chemistry, engineering, and increasingly bio-related materials. This meeting will be held in early Fall at a venue near NSF. The workshop discussions will be focused on 4 topics: (1) Educating the public about the relevance of materials research through successful outreach; (2) Materials education for K-12 students and teachers; (3) Revolutionalizing undergraduate education toward flexible curriculum that includes multidisciplinary training; (4) Materials education for graduate students to prepare materials scientists and engineers with the skills to succeed in today's global research and development environment. The participants are expected to be those in a position to introduce change in the educational programs not only at their institutions but on a national level.

The meeting format includes half-day sessions consisting of keynote speeches and break-out group discussions followed by a common panel discussion on each topic. The anticipated outcome is a roadmap to enhance materials science and materials engineering education at all levels. A report which captures the conference discussions and recommendations to guide future planning by the materials community, professional societies, funding agencies, and others with strong materials education initiatives will be published within a few months following the conference.

This workshop is jointly funded by the Division of Materials Research(DMR), Physics (PHY), and the Office of Multidisciplinary Activities (OMA) within the Mathematical and Physical Sciences (MPS) directorate and by the Division of Research on Learning in Formal and Informal Settings (DRL) and Undergraduate Education (DUE) in the Education and Human Resources directorate.

This project is awarded under the Nanoelectronics for 2020 and Beyond competition, with support by multiple Directorates and Divisions at the National Science Foundation as well as by the Nanoelectronics Research Initiative of the Semiconductor Research Corporation.

TECHNICAL: The research project explicitly addresses key scientific and technological challenges that, if overcome, could lead to a possible replacement for conventional electronics made from silicon. The novel nanoelectronics platform is based upon remarkable properties of materials composed of lanthanum aluminate and strontium titanate. The interface between these two oxide materials can be switched between an insulating and a metallic state using a sharp conducting probe. Electronic circuits can be "written" and "erased" at scales approaching the distance between atoms (two nanometers). To develop useful electronics, it is imperative to develop a scheme capable of creating and manipulating large numbers of devices. This scaling is achieved through the use of large probe arrays. Each probe must be capable of addressing multiple sites, enabling complex circuits to be fabricated on a single chip, by the device itself. The oxide heterostructures need to be grown on large manufacturable substrates: this has been demonstrated with both silicon and one other material. The research project addresses many of the core requirements for a reconfigurable storage, computing, and optical sensing platform that can scale beyond what is currently possible for silicon. The interdisciplinary research team directly addresses these scientific and technological challenges with the variety of perspectives essential for the development of breakthrough technologies.

NON-TECHNICAL: This project seeks to transform exciting scientific achievements into cutting-edge information technologies. The research directly addresses the need for scaling beyond Moore's law and has the potential to create new high-tech industries, thus creating new jobs in the US that require advanced skill sets. To help address the need for highly trained workers and researchers, a new OnRamp education program is designed that specifically targets difficulties that students have in their sub-discipline while beginning their careers. OnRamp tutorials are developed by beginning graduate students as they learn the ropes of doing research. Graduate students help develop research-based learning modules, which are shared with a broader research community. Both University of Wisconsin and University of Pittsburgh continue and expand their high school outreach programs aimed at increasing the numbers of students in underrepresented groups in science and engineering disciplines.

This award supports the continued development, assessment, and dissemination of Quantum Interactive Learning Tutorials (QuILT) and peer-instruction tools for undergraduate courses to prepare future scientists and engineers for the demands of the high-tech workplace. A solid grasp of the fundamental principles of quantum physics is essential for most scientists and engineers, considering that the global economy has become increasingly dependent on science and technology based upon quantum phenomena. Single electron transistors, SQUIDs, quantum-well lasers, and other innovative quantum devices are made possible by an understanding of the underlying quantum processes. However, quantum physics is a technically difficult and abstract subject. The subject matter makes instruction quite challenging; able students constantly struggle to master basic concepts. To sustain U.S. leadership in science and technology, it is critical to ensure that advanced undergraduate students (and graduate students) preparing for careers in science and engineering develop a solid grasp of the fundamental concepts of quantum physics.

QuILTs and peer-instruction tools are based upon a cognitive-apprenticeship model of learning and emphasize modeling, coaching and weaning. To aid instructors, the concept-based and problem-based QuILTs and peer-instruction tools will be keyed with most of the common textbooks. However, every effort will be made to ensure that the different modules fit together as a coherent whole and help students organize their knowledge in a hierarchical fashion. Some tools expose students to contemporary and exciting topics such as quantum cryptography that can be taught using simple two-level systems.

Numerous reports from government and industry have called for colleges and universities to produce more -- and more capable -- STEM graduates. To attract more students to STEM fields, faculty need to make the curriculum more engaging and relevant. One important shift in instructional approach is to replace traditional laboratory courses with discovery-based courses, giving students exposure to research techniques and equipment. In this project, the investigators will employ a set of design principles to reform three lab experiments used in advanced physics lab courses. The design principles include using research-grade techniques and equipment, encouraging exploration and collaboration in teams, and having students learn to debug experiments by following signals (optical, electrical, etc.) through the experiments as a researcher would. The new labs will provide students an opportunity to design experiments and explore outcomes, provide sufficient flexibility so that students are challenged to take control and reflect upon the direction of the experiments, and provide students an opportunity to perform progressively more complex analyses of experiments. The reformed experiments will be implemented at a reasonable cost and will include completely open hardware and software. The investigators will assess the effectiveness of the reformed experiments by comparing the performance and experiences of students completing the experiments before and after the changes are implemented.

Traditional physics lab exercises often do not provide students with authentic experiences to help them develop problem-solving, reasoning, and higher-order thinking skills and learn to think like a physicist. The three reformed labs to be developed in this project (i.e., acoustic resonance, Mossbauer spectroscopy, and noise and filtering) will use a cognitive approach to instructional design and will take into account students' prior knowledge in determining the level of support provided at a given stage of exploration and analysis. In particular, the investigators will apply a field-tested cognitive apprenticeship model in which the instructor will model the criteria of good performance, coach students and provide an appropriate level of scaffolding support, and then reduce the support so that the students develop self-reliance in the design and explorations in the labs. The principles, hardware, and software used in redesigning the physics lab exercises can be adapted to redesign experiments in other STEM fields.

The University of Pittsburgh has received an NSF Improving Undergraduate STEM Education: Education and Human Resources Design and Development tier award to bring together a highly interdisciplinary team to study a suite of instructional, cognitive-skill, and social/motivational interventions that have been demonstrated to produce large improvements in learning in the context of introductory STEM courses. This research is significant because it will allow us to understand which interventions produce long-term positive outcomes, whether these interventions combine negatively or synergistically within and across courses, and the types of situations or groups of students for which they are most effective.

The project team consists of four Discipline-Based Education Research scientists (biology, chemistry, physics, and psychology), three learning scientists with expertise in social/motivational, cognitive skills or active STEM learning techniques, and a learning scientist with expertise in large-scale longitudinal data analysis with cutting edge statistical techniques. This project represents the initial phase of a new type of study termed "Intervention Science." Although interventions are relatively commonplace in educational settings, very little research has sought to comprehensively evaluate different interventions in a single, interdisciplinary methodological framework. The research plan seeks to understand the relative influence of different classroom "interventions" (e.g. "flipped" classes, active learning, peer assessment, etc.) on indicators of student success (e.g. course performance in downstream courses, participation in undergraduate research, conceptual learning gains, etc.). Construction of control and experimental groups will be accomplished using statistical techniques that assign students probabilistically to such categories. Confounding circumstances (e.g. students enrolled in different courses experiencing different interventions, or students interacting with peers in other courses) will be handled using techniques such as hierarchical linear modeling. Knowledge of the conditions in which instructional, cognitive-skill, and social/motivational interventions are most effective, and on whom, will inform the way in which faculty members implement effective interventions in the classroom and, in that way, have a significant impact on the educational experience of large numbers of STEM students nationwide.

This award funds a project to develop materials that will help students understand the challenging topics in quantum mechanics. The aim is to prepare future scientists and engineers for the demands of the high-tech workplace with its growing dependence on quantum phenomena through the continued development, assessment, and dissemination of Quantum Interactive Learning Tutorials (QuILT) and peer-instruction tools for undergraduate course. QuILTs and peer-instruction tools use research as a guide and are based on a cognitive-apprenticeship model emphasizing modeling, coaching and weaning. Guidance and effective methods of education are critical in retaining students in science and in shaping their career choices.

The curriculum features that make these products particularly suited for the challenging task of teaching quantum physics are: (1) They are based upon research in physics education and pay particular attention to cognitive issues. (2) They consistently keep students engaged in the learning process by asking them to predict what should happen in a particular situation and then providing appropriate feedback. (3) They employ visualization tools to help students build physical intuition about quantum processes. (4) They attempt to bridge the gap between the abstract quantitative formalism of quantum mechanics and the qualitative understanding necessary to explain and predict diverse physical phenomena. (5) They are based on systematic investigations of difficulties students have in learning various concepts in quantum physics. (6) Many of the tools can be used in class by the instructors as supplements to lectures or outside of the class as homework or as self-study tool by students. (7) They consist of self-sufficient modular units that can be used in any order that is convenient. These tools can also be used by graduate students who may need to refresh concepts learned in undergraduate quantum mechanics as a self-study tool. This award is co-funded by the Division of Physics Integrative Activities in Physics Program within the Mathematical and Physical Sciences Directorate and by the Division of Undergraduate Education within the Education and Human Resources Directorate.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.