Raji A Shankar

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We develop an asymptotically exact renormalization-group approach that treats electron-electron and electron-phonon interactions on an equal footing. The approach allows an unbiased study of the instabilities of Fermi liquids without the assumption of a broken symmetry. We apply our method to the problem of strongly coupled superconductors and find the(More)
Complementary metal–oxide–semiconductor compatible athermal silicon nitride/titanium dioxide hybrid micro-ring resonators Appl. Application of zero-index metamaterials for surface plasmon guiding Appl. Photonic crystal coupled cavities with increased beaming and free space coupling efficiency Appl. Efficient coupler between silicon photonic and(More)
Dynamically reconfigurable metasurfaces open up unprecedented opportunities in applications such as high capacity communications, dynamic beam shaping, hyperspectral imaging, and adaptive optics. The realization of high performance metasurface-based devices remains a great challenge due to very limited tuning ranges and modulation depths. Here we show that(More)
Ischemic tissues generate nitric oxide (NO) by direct reduction of tissue nitrite under the acidic conditions that occur during ischemia. In view of the important implications of this enzyme-independent mechanism of NO generation on the pathogenesis and treatment of tissue injury, the NO formation in mice subjected to cardiopulmonary arrest was measured and(More)
Piperidine nitroxides have considerable clinical potential, both as antioxidant therapeutic compounds and contrast agents in magnetic resonance imaging. However, their development has thus far been limited by their rapid bioreduction in vivo. Recently, it was reported that polynitroxyl albumin (PNA) can reverse the bioreduction of the reduced(More)
Graphene is an attractive photoconductive material for optical detection due to its broad absorption spectrum and ultrashort response time. However, it remains a great challenge to achieve high responsivity in graphene detectors because of graphene's weak optical absorption (only 2.3% in the monolayer graphene sheet) and short photocarrier lifetime (<1 ps).(More)
BACKGROUND Myeloid-related protein 8 (MRP8) and MRP14 are S100 family calcium binding proteins that form a heterodimer known as calprotectin or MRP8/14 that is present in the cytosol of neutrophils and monocytes. MRP8/14 becomes associated with endothelium at sites of monocyte and neutrophil adhesion and transmigration and induces a thrombogenic and(More)
Graphene is emerging as a broadband optical material which can be dynamically tuned by electrostatic doping. However, the direct application of graphene sheets in optoelectronic devices is challenging due to graphene's small thickness and the resultant weak interaction with light. By combining metal and graphene in a hybrid plasmonic structure, it is(More)
Quantum dots pose a problem where one must confront three obstacles: randomness, interactions and finite size. Yet it is this confluence that allows one to make some theoretical advances by invoking three theoretical tools: Random Matrix theory (RMT), the Renormalization Group (RG) and the 1/N expansion. Here the reader is introduced to these techniques and(More)
This is an introduction to the microscopic theories of the FQHE. After a brief description of experiments, trial wavefunctions and the physics they contain are discussed. This is followed by a description of the hamiltonian approach, wherein one goes from the electrons to the composite fermions by a series of transformations. The theory is then compared to(More)