Clay, R. T., Mazumdar, S., Li, H.
We suggest that superconductivity (SC) in the organic charge transfer solids (CTS) is reached from a Bond-Charge Density Wave (BCDW). We discuss an effective model for the BCDW to SC transition, an...
Mazumdar, S., Clay, R. T., Li, H.
We show that superconductivity is absent within the 1/2-filled band triangular lattice repulsive Hubbard model that has been proposed for organic charge-transfer solids. We posit that organic...
Clay, R. T., Li, H., Mazumdar, S.
We report exact calculations of magnetic and superconducting pair-pair correlations for the half-filled band Hubbard model on an anisotropic triangular lattice. Our results for the magnetic phases...
We demonstrate a robust frustration-driven charge-order to superconductivity transition in the half-filled negative-U extended Hubbard model. Superconductivity extends over a broad region of the...
Musfeldt, J. L., Brown, S., Mazumdar, S., Clay, R. T., Mas-Torent, M., Rovira, C., ...
We measured the variable temperature infrared response of the spin ladder candidate (DTTTF)2Cu(mnt)2 in order to distinguish between two competing ladder models, rectangular versus zigzag, proposed...
Khanna, S, Talukdar, R, Saikia, N, Mazumdar, S, Kulkarni, S, Vij, J, ...
Pinned Low Energy Electronic Excitation in Metal Exchanged Vanadium Oxide Nanoscrolls (2007)
Cao, J., Musfeldt, J. L., Mazumdar, S., Chernova, N., Whittingham, M. S.
We measured the optical properties of mixed valent vanadium oxide nanoscrolls and their metal exchanged derivatives in order to investigate the charge dynamics in these compounds. In contrast to the...
Clay, R. T., Hardikar, R. P., Mazumdar, S.
It is known that within the interacting electron model Hamiltonian for the one-dimensional 1/4-filled band, the singlet ground state is a Wigner crystal only if the nearest neighbor electron-electron...
Yan, Y., Mazumdar, S., Ramasesha, S.
We report density-matrix renormalization group calculations of spin gaps in the quarter-filled correlated two-leg rectangular ladder with bond-dimerization along the legs of the ladder. In the small...
Das, Mousumi, Ramasesha, S, Mazumdar, S
We investigate the possibility that high-energy singlet and triplet excited states with large electron-hole separations are generated in electron-hole recombination process, over and above the lowest...
We report accurate numerical studies of excited state orderings in long hypothetical pi-conjugated oligomers in which the hydrogen atoms of trans-polyacetylene are replaced with conjugated...
Controlling quantum transport through a single molecule (2005)
Cardamone, D. M., Stafford, C. A., Mazumdar, S.
We investigate multi-terminal quantum transport through single monocyclic aromatic annulene molecules, and their derivatives, using the nonequilibrium Green function approach in the self-consistent...
Zhao, H., Mazumdar, S., Vardeny, Z. V.
The nature of the primary photoexcitations in semiconducting single-walled carbon nanotubes (S-SWCNTs) is of strong current interest. We have studied the emission spectra of S-SWCNTs and two...
Electroabsorption spectroscopy of single walled nanotubes (2005)
Kennedy, J. W., Vardeny, Z. V., Collins, S., Baughman, R. H., Zhao, H., Mazumdar, S.
We have measured the electric field modulated absorption of a sample of single-walled nanotubes (SWNT) suspended in a solid polyvinyl alcohol matrix. The electroabsorption (EA) spectrum roughly...
The Quantum Interference Effect Transistor (2005)
Cardamone, D. M., Stafford, C. A., Mazumdar, S.
We propose a new type of molecular transistor, the Quantum Interference Effect Transistor (QuIET), based on tunable current suppression due to quantum interference. We show that any aromatic...
Das, Mousumi, Ramasesha, S, Mazumdar, S
We investigate the possibility that high-energy singlet and triplet excited states with large electron-hole separations are generated in electron-hole recombination process, over and above the lowest...
New Mechanisms and New Materials for Organic Optical Nonlinearity (2005)
Peyghambarian, N., Mazumdar, S., Armstrong, N.
In order to be photorefractive, a material has to combine photogeneration, photoconductivity, trapping and electro-optic (EO) properties. For our work we have developed a guest/host polymer composite...
Das, Mousumi, Mazumdar, S., Ramasesha, S.
We extend our theory of electron--hole recombination in organic light emitting diodes to investigate the possibility that high energy singlet and triplet excited states with large electron--hole...
Magnetism in BEDT-TTF materials (2004)
Strong commensurate antiferromagnetism proximate to superconductivity is found in some members of the kappa-(ET) family, while a spin gap (SG) is found in the theta-(ET). Both kappa- and theta-(ET)...
Co-operative density wave and giant spin gap in the quarter-filled zigzag ladder (2004)
Strong co-operative interactions occur between four different broken symmetries involving charge-ordering and bond distortions in the quarter-filled correlated zigzag electron ladder. The ground...
Mazumdar, S., Das, Mousumi, Ramasesha, S.
The low-lying singlet and triplet spectrum in conjugated polymers clearly show that the mechanism proposed by Lin et al. to explain their electric field dependence of singlet to triplet yield ratios...
Ramasesha, S, Mazumdar, S, Tandon, Kunj, Das, Mousumi
Using a time-dependent model many-body formulation, we follow the electron–hole recombination between a pair of oppositely charged polyene chains and triplet–triplet (T–T) scattering in...
Rung-singlet charge-ordering in alpha'-NaV2O5 (2003)
We show that the proposed zig--zag charge--ordering model for alpha'--NaV2O5 is incompatible with a single transition that induces both charge--ordering and spin gap. We introduce a two--band model...
Designing pi-conjugated polymers with light emission in the infrared (2003)
Mazumdar, S., Dallakyan, S., Chandross, M.
There is currently a great need for solid state lasers that emit in the infrared. Whether or not conjugated polymers that emit in the IR can be synthesized is an interesting theoretical challenge. We...
Theory of excited state absorptions in phenylene-based $\pi$-conjugated polymers (2003)
Shukla, Alok, Ghosh, Haranath, Mazumdar, S.
Within a rigid-band correlated electron model for oligomers of poly-(paraphenylene) (PPP) and poly-(paraphenylenevinylene) (PPV), we show that there exist two fundamentally different classes of...
Electron correlation effects in electron-hole recombination in organic light-emitting diodes (2003)
Tandon, Kunj, Ramasesha, S, Mazumdar, S
We develop a general theory of electron-hole recombination in organic light-emitting diodes that leads to formation of emissive singlet excitons and nonemissive triplet excitons. We briefly review...
Electron correlation effects in electron-hole recombination in organic light-emitting diodes (2003)
Tandon, Kunj, Ramasesha, S, Mazumdar, S
We develop a general theory of electron-hole recombination in organic light-emitting diodes that leads to formation of emissive singlet excitons and nonemissive triplet excitons. We briefly review...
Ramasesha, S, Mazumdar, S, Tandon, Kunj, Das, Mousumi
Using a time-dependent model many-body formulation, we follow the electron–hole recombination between a pair of oppositely charged polyene chains and triplet–triplet (T–T) scattering in...
Universal banking under bilateral information asymmetry. (2002)
Banerji, S., Chen, A., Mazumdar, S.
The Gramm–Leach–Bliley (GLB) Act of 1999 repealed many provisions of the Glass–Steagall Act that curtailed competition between banks and commercial firms. Significantly, however, the GLB Act...
Dallakyan, S., Chandross, M., Mazumdar, S.
There is currently a great need for solid state lasers that emit in the infrared, as this is the operating wavelength regime for applications in telecommunications. Existing $\pi$--conjugated...
The ubiquitous 1100 charge ordering in organic charge-transfer solids (2002)
Mazumdar, S., Clay, R. T., Campbell, D. K.
Charge and spin-orderings in the 1/4-filled organic CT solids are of strong interest, especially in view of their possible relations to organic superconductivity. We show that the charge order (CO)...
Sub-Poissonian Shot Noise in Molecular Wires (2002)
We investigate the transport behavior of polyene molecules sandwiched between two metallic contacts using the non-equilibrium Green's function formalism. We calculate both current and noise power as...
Electron correlation effects in electron-hole recombination in organic light-emitting diodes (2002)
Tandon, K., Ramasesha, S., Mazumdar, S.
We develop a general theory of electron--hole recombination in organic light emitting diodes that leads to formation of emissive singlet excitons and nonemissive triplet excitons. We briefly review...
Electron-hole versus exciton delocalization in conjugated polymers: the role of topology (2002)
Dallakyan, S., Chandross, M., Mazumdar, S.
There is currently a great need for solid state lasers that emit in the infrared. Whether or not conjugated polymers that emit in the IR can be synthesized is an interesting theoretical challenge. We...
Charge ordering in theta-(BEDT-TTF)_2 X materials (2002)
Clay, R. T., Mazumdar, S., Campbell, D. K.
We investigate theoretically charge ordered states on the anisotropic triangular lattice characteristic of the theta-(BEDT-TTF)_2 X materials. Using exact diagonalization studies, we establish that...
Clay, R. T., Mazumdar, S., Campbell, D. K.
We examine critically two different recently proposed models of charge ordering in the nominally 1/4-filled organic charge transfer solids (CTS). In one dimension, the two models are characterized by...
Comment on Phys. Rev. Lett. 86, 2086 (2001)
Dimensionality dependence of optical nonlinearity and relaxation dynamics in cuprates (2001)
Ashida, M., Taguchi, Y., Tokura, Y., Clay, R. T., Mazumdar, S., Svirko, Yu. P., ...
Femtosecond pump-probe measurements find pronounced dimensionality dependence of the optical nonlinearity in cuprates. Although the coherent two-photon absorption (TPA) and linear absorption bands...
Re-integerization of fractional charges in the correlated quarter-filled band (2000)
Clay, R. T., Mazumdar, S., Campbell, D. K.
Previous work has demonstrated the existence of soliton defect states with charges +/- e/2 in the limits of zero and of infinite on-site Coulomb interactions in the one-dimensional (1D)...
Mazumdar, S., Clay, R. T., Campbell, D. K.
We report two surprising results regarding the nature of the spatial broken symmetries in the two-dimensional (2D), quarter-filled band with strong electron-electron interactions. First, in direct...
Ultrafast optical nonlinearity in quasi-one-dimensional Mott-insulator ${\rm Sr_2CuO_3}$ (2000)
Ogasawara, T., Ashida, M., Motoyama, N., Eisaki, H., Uchida, S., Tokura, Y., ...
We report strong instantaneous photoinduced absorption (PA) in the quasi-one-dimensional Mott insulator ${\rm Sr_2CuO_3}$ in the IR spectral region. The observed PA is to an even-parity two-photon...
Mazumdar, S., Clay, R. T., Campbell, D. K.
Two-dimensional (2D) strongly correlated electron systems underlie many of the most important phenomena in contemporary condensed matter physics, including the Quantum Hall Effect (QHE), ``high T_c''...
Push vs. Pull in Web-Based Network Management (1999)
In M. Sloman, S. Mazumdar, E. Lupu (eds
In this paper, we build on the concept of embedded management application, proposed by Wellens and Auerbach, and present two models of network management application designs that rely on Web...
Infinite Volume Extrapolations of Finite Cluster Calculations-How Correct Are These. (1998)
Mazumdar, S., Guo, F., Guo, D., Ung, K-C, Gammel, J. T.
Extrapolations of numerical data obtained from finite cluster calculations to the infinite volume limit can often give incorrect results. We discuss four separate cases: (a) the intensity of the...
An Organic Thin Film Laser Diode: A Novel Light Source. (1998)
Peyghambarian, N., Armstrong, N. R., Hall, H., Padias, A., Mazumdar, S.
Our proposal to ONR focused on the development of an entirely new diode laser based upon electroluminescent organic thin films. We proposed to develop new polymers for this important application. As...
Mazumdar, S., Ramasesha, S., Clay, R. T., Campbell, D. K.
Recent experiments indicate that the spin-density waves (SDWs) in (TMTTF)_2Br, (TMTSF)_2PF_6 and alpha-(BEDT-TTF)_2MHg(SCN)_4 are highly unconventional and coexist with charge-density waves (CDWs)....
An Organic Thin Film Laser Diode: A New and Novel Light Source. (1997)
Peyghambarian, N., Mazumdar, S., Armstrong, N., Kippelen, B.
This ONR program was focusing on the development of an entirely new diode laser, based upon electroluminescent organic thin films. During these three years, important milestones have been reached...
New Mechanisms and New Materials for Organic Optical Nonlinearity. (1997)
Peyghambarian, N., Mazumdar, S., Armstrong, N.
This program has been extremely successful with over 50 publications and presentations (see the enclosed publication list). During this period, we had two publications in Nature, two in Physical...
Ung, K. C., Mazumdar, S., Toussaint, D.
The theory of the 2k_F and 4k_F instabilities in quarter-filled band organic conductors is revisited. The phase angles of the 2k_F bond and charge density waves are shown to change as electron...
Pairing on Small Clusters in the Peierls-Hubbard Model: Implications for C$_{60}$ (1993)
Guo, D., Ung, K. C., Mazumdar, S.
We study the pairing within the Peierls-Hubbard Model for electron- and hole-doped analogs of C$_{60}$ accessible to exact diagonalization techniques (cube, truncated tetrahedron, {\it etc.}). We...
Infinite Volume Extrapolations of Finite Cluster Calculations, ---How Correct are These? (1993)
Mazumdar, S., Guo, F., Guo, D., Gammel, J. Tinka
Extrapolations of numerical data obtained from finite cluster calculations to the infinite volume limit can often give incorrect results. We discuss four separate cases: (a) the intensity of the...
Organic Superconductivity: An Experiment Based Theory (1988)
Within the last decade the superconducting critical temperature in the organics has gone up from about 1K to greater than 10K, but the search for a comprehensive theory is still on. A completely...
Organic Superconductivity: An Experiment Based Theory (1988)
Within the last decade the superconducting critical temperature in the organics has gone up from about 1K to greater than 10K, but the search for a comprehensive theory is still on. A completely...
Sau, A K, Chen, C A, Cowan, J A, Mazumdar, S, Mitra, S
Detailed circular dichroism (CD), steady-state and time-resolved tryptophan fluorescence studies on the holo- and apo- forms of high potential iron protein (HiPIP) from Chromatium vinosum and its...
Recent developments in the multistage modeling of cohort data for carcinogenic risk assessment.
Mazumdar, S, Redmond, C K, Costantino, J P, Patwardhan, R N, Zhou, S Y
The modeling of cohort data based on the Armitage-Doll multistage model of the carcinogenic process has gained popular acceptance as a methodology for quantitative risk assessment for estimating the...
A controlled test of the use of registered nurses for prenatal care.
Schlesinger, E R, Lowery, W D, Glaser, D B, Milliones, M D, Mazumdar, S
Mazumdar, S, Colbus, D S, Townsend, M C
The assumption that discharge diagnoses of chronic obstructive pulmonary disease and other allied conditions accurately reflect patient medical records was tested using a sample of 553 hospital...
Sau, A K, Chen, C A, Cowan, J A, Mazumdar, S, Mitra, S
Detailed circular dichroism (CD), steady-state and time-resolved tryptophan fluorescence studies on the holo- and apo- forms of high potential iron protein (HiPIP) from Chromatium vinosum and its...
Recent developments in the multistage modeling of cohort data for carcinogenic risk assessment.
Mazumdar, S, Redmond, C K, Costantino, J P, Patwardhan, R N, Zhou, S Y
The modeling of cohort data based on the Armitage-Doll multistage model of the carcinogenic process has gained popular acceptance as a methodology for quantitative risk assessment for estimating the...
A controlled test of the use of registered nurses for prenatal care.
Schlesinger, E R, Lowery, W D, Glaser, D B, Milliones, M D, Mazumdar, S
Mazumdar, S, Colbus, D S, Townsend, M C
The assumption that discharge diagnoses of chronic obstructive pulmonary disease and other allied conditions accurately reflect patient medical records was tested using a sample of 553 hospital...
Das, K. M., Vecchi, M., Novikoff, A., Mazumdar, S., Novikoff, P. M.
Injections of Crohn's disease (CD) tissue filtrates produce lymphoma and hyperplastic lymph nodes from plasma cell hyperplasia (PCH) in athymic nude (nu/nu) mice; these lymphoid tissue contain an...