School of Humanities and Sciences
Showing 1-10 of 20 Results
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Shamit Kachru
Professor of Physics and Director, Stanford Institute for Theoretical Physics, Emeritus
Current Research and Scholarly InterestsMy current research is focused in three directions:
— Mathematical aspects of string theory (with a focus on BPS state counts, black holes, and moonshine)
— Quantum field theory approaches to condensed matter physics (with a focus on physics of non-Fermi liquids)
— Theoretical biology, with a focus on evolution and ecology -
Renata Kallosh
Stanford W. Ascherman, MD Professor, Emerita
BioWhat is the mathematical structure of supergravity/string theory and its relation to cosmology?
Professor Kallosh works on the general structure of supergravity and string theory and their applications to cosmology. Her main interests are related to the models early universe inflation and dark energy in string theory. She develops string theory models explaining the origin of the universe and its current acceleration. With her collaborators, she has recently constructed de Sitter supergravity, which is most suitable for studies of inflation and dark energy and spontaneously broken supersymmetry.
She is analyzing possible consequences of the expected new data from the Large Hadron Collider (LHC) and the results of current and future cosmological observations, including Planck satellite CMB data. These results may affect the relationship between superstring theory and supergravity, and the real world. Professor Kallosh works, in particular, on future tests of string theory by CMB data and effective supergravity models with flexible amplitude of gravitational waves produced during inflation. -
Matthew Kanan
Associate Professor of Chemistry
BioAssociate Professor of Chemistry Matthew Kanan develops new catalysts and chemical reactions for applications in renewable energy conversion and CO2 utilization. His group at Stanford University has recently developed a novel method to create plastic from carbon dioxide and inedible plant material rather than petroleum products, and pioneered the study of “defect-rich” heterogeneous electro-catalysts for converting carbon dioxide and carbon monoxide to liquid fuel.
Matthew Kanan completed undergraduate study in chemistry at Rice University (B.A. 2000 Summa Cum Laude, Phi Beta Kappa). During doctoral research in organic chemistry at Harvard University (Ph.D. 2005), he developed a novel method for using DNA to discover new chemical reactions. He then moved into inorganic chemistry for his postdoctoral studies as a National Institutes of Health Postdoctoral Research Fellow at the Massachusetts Institute of Technology, where he discovered a water oxidation catalyst that operates in neutral water. He joined the Stanford Chemistry Department faculty in 2009 to continue research into energy-related catalysis and reactions. His research and teaching have already been recognized in selection as one of Chemistry & Engineering News’ first annual Talented 12, the Camille Dreyfus Teacher-Scholar Award, Eli Lilly New Faculty Award, and recognition as a Camille and Henry Dreyfus Environmental Mentor, among other honors.
The Kanan Lab addresses fundamental challenges in catalysis and synthesis with an emphasis on enabling new technologies for scalable CO2 utilization. The interdisciplinary effort spans organic synthesis, materials chemistry and electrochemistry.
One of the greatest challenges of the 21st century is to transition to an energy economy with ultra-low greenhouse gas emissions without compromising quality of life for a growing population. The Kanan Lab aims to help enable this transition by developing catalysts and chemical reactions that recycle CO2 into fuels and commodity chemicals using renewable energy sources. To be implemented on a substantial scale, these methods must ultimately be competitive with fossil fuels and petrochemicals. With this requirement in mind, the group focuses on the fundamental chemical challenge of making carbon–carbon (C–C) bonds because multi-carbon compounds have higher energy density, greater value, and more diverse applications that one-carbon compounds. Both electrochemical and chemical methods are being pursued. For electrochemical conversion, the group studies how defects known as grain boundaries can be exploited to improve CO2/CO electro-reduction catalysis. Recent work has unveiled quantitative correlations between grain boundaries and catalytic activity, establishing a new design principle for electrocatalysis, and developed grain boundary-rich copper catalysts with unparalleled activity for converting carbon monoxide to liquid fuel. For chemical CO2 conversion, the group is developing C–H carboxylation and CO2 hydrogenation reactions that are promoted by simple carbonate salts. These reactions provide a way to make C–C bonds between un-activated substrates and CO2 without resorting to energy-intensive and hazardous reagents. Among numerous applications, carbonate-promoted carboxylation enables the synthesis of a monomer used to make polyester plastic from CO2 and a feedstock derived from agricultural waste.
In addition to CO2 chemistry, the Kanan group is pursuing new strategies to control selectivity in molecular catalysis for fine chemical synthesis. Of particular interest in the use of electrostatic interactions to discriminate between competing reaction pathways based on their charge distributions. This effort uses ion pairing or interfaces to control the local electrostatic environment in which a reaction takes place. The group has recently shown that local electric fields can control regioselectivity in isomerization reactions catalyzed by gold complexes. -
Aharon Kapitulnik
Theodore and Sydney Rosenberg Professor of Applied Physics and Professor of Physics
BioAharon Kapitulnik is the Theodore and Sydney Rosenberg Professor in Applied Physics at the Departments of Applied Physics and Physics at Stanford University. His research focuses on experimental condensed matter physics, while opportunistically, also apply his methods to tabletop experimental studies of fundamental phenomena in physics. His recent studies cover a broad spectrum of phenomena associated with the behavior of correlated and disordered electron systems, particularly in reduced dimensions, and the development of effective instrumentation to detect subtle signatures of physical phenomena.
Among other recognitions, his activities earned him the Alfred P. Sloan Fellowship (1986-90), a Presidential Young Investigator Award (1987-92), a Sackler Scholar at Tel-Aviv University (2006), the Heike Kamerlingh Onnes Prize for Superconductivity Experiment (2009), a RTRA (Le Triangle de la Physique) Senior Chair (2010), and the Oliver Buckley Condensed Matter Prize of the American Physical Society (2015). Aharon Kapitulnik is a Fellow of the American Physical Society, a Fellow of the American Academy of Arts and Sciences, a Fellow of the American Association for the Advancement of Science and a member of the National Academy of Sciences. Kapitulnik holds a Ph.D. in Physics from Tel-Aviv University (1984). -
Hemamala Karunadasa
Associate Professor of Chemistry and Senior Fellow at the Precourt Institute for Energy
BioProfessor Hema Karunadasa works with colleagues in materials science, earth science, and applied physics to drive the discovery of new materials with applications in clean energy. Using the tools of synthetic chemistry, her group designs materials that couple the structural tunability of organic molecules with the diverse electronic and optical properties of extended inorganic solids. This research targets materials such as sorbents for capturing environmental pollutants, phosphors for solid-state lighting, and absorbers for solar cells.
Hemamala Karunadasa studied chemistry and materials science at Princeton University (A.B. with high honors 2003; Certificate in Materials Science and Engineering 2003), where her undergraduate thesis project with Professor Robert J. Cava examined geometric magnetic frustration in metal oxides. She moved from solid-state chemistry to solution-state chemistry for her doctoral studies in inorganic chemistry at the University of California, Berkeley (Ph.D. 2009) with Professor Jeffrey R. Long. Her thesis focused on heavy atom building units for magnetic molecules and molecular catalysts for generating hydrogen from water. She continued to study molecular electrocatalysts for water splitting during postdoctoral research with Berkeley Professors Christopher J. Chang and Jeffrey R. Long at the Lawrence Berkeley National Lab. She further explored molecular catalysts for hydrocarbon oxidation as a postdoc at the California Institute of Technology with Professor Harry B. Gray. She joined the Stanford Chemistry Department faculty in September 2012. Her research explores solution-state routes to new solid-state materials.
Professor Karunadasa’s lab at Stanford takes a molecular approach to extended solids. Lab members gain expertise in solution- and solid-state synthetic techniques and structure determination through powder- and single-crystal x-ray diffraction. Lab tools also include a host of spectroscopic and electrochemical probes, imaging methods, and film deposition techniques. Group members further characterize their materials under extreme environments and in operating devices to tune new materials for diverse applications in renewable energy.
Please visit the lab website for more details and recent news. -
Chaitan Khosla
Wells H. Rauser and Harold M. Petiprin Professor and Professor of Chemistry and, by courtesy, of Biochemistry
Current Research and Scholarly InterestsResearch in this laboratory focuses on problems where deep insights into enzymology and metabolism can be harnessed to improve human health.
For the past two decades, we have studied and engineered enzymatic assembly lines called polyketide synthases that catalyze the biosynthesis of structurally complex and medicinally fascinating antibiotics in bacteria. An example of such an assembly line is found in the erythromycin biosynthetic pathway. Our current focus is on understanding the structure and mechanism of this polyketide synthase. At the same time, we are developing methods to decode the vast and growing number of orphan polyketide assembly lines in the sequence databases.
For more than a decade, we have also investigated the pathogenesis of celiac disease, an autoimmune disorder of the small intestine, with the goal of discovering therapies and related management tools for this widespread but overlooked disease. Ongoing efforts focus on understanding the pivotal role of transglutaminase 2 in triggering the inflammatory response to dietary gluten in the celiac intestine.
