192 citations · 1.3k across the 69 of their papers we have counts for
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Quantum phase transition in skewed ladders: an entanglement entropy and fidelity study
Sambunath Das, Dayasindhu Dey, S. Ramasesha +1
Entanglement entropy (EE) of a state is a measure of correlation or entanglement between two parts of a composite system and it may show appreciable change when the ground state (G…
Quantum phases of spin-1 system on 3/4 and 3/5 skewed ladders
Sambunath Das, Dayasindhu Dey, S. Ramasesha +1
We study the quantum phase transitions of frustrated antiferromagnetic Heisenberg spin-1 systems on the 3/4 and 3/5 skewed two leg ladder geometries. These systems can be viewed as…
Quantum phases of a frustrated spin-1 system: The 5/7 skewed ladder
Sambunath Das, Dayasindhu Dey, Manoranjan Kumar +1
The quantum phases in a spin-1 skewed ladder system formed by alternately fusing five- and seven-membered rings are studied numerically using the exact diagonalization technique up…
Study of magnetization relaxation in molecular spin clusters using an innovative kinetic Monte Carlo method
Sumit Haldar, S. Ramasesha
Modeling blocking temperature in molecular magnets has been a long standing problem in the field of molecular magnetism. We investigate this problem using a kinetic Monte Carlo (kM…
Magnetization plateaus of spin- system on a 5/7 skewed ladder
Dayasindhu Dey, Sambunath Das, Manoranjan Kumar +1
Magnetization plateaus are some of the most striking manifestations of frustration in low-dimensional spin systems. We present numerical studies of magnetization plateaus in the fa…
Magnetocaloric effect in molecular spin clusters and their assemblies: model exact and Monte Carlo studies
Sumit Haldar, S. Ramasesha
We study the magnetocaloric effect (MCE) in spin clusters of six spins with site spins , and for different exchange anisotropies. We also study MCE in an assembly of…
The Correlated Electronic States of a few Polycyclic Aromatic Hydrocarbons: A Computational Study
Geetanjali Giri, Anusooya Y. Pati, S. Ramasesha
In recent years Polycyclic Aromatic Hydrocarbons (PAHs) have been studied for their electronic properties as they are viewed as nanodots of graphene. They have also been of interes…
A model Exact Study of the properties of low-lying electronic states of Perylene and Substituted Perylenes
Geetanjali Giri, Suryoday Prodhan, Y. Anusooya Pati +1
There is a resurgence of interest in the electronic structure of perylene for its applications in molecular devices such as organic photovoltaics and organic light emitting diodes.…
Quantum phases of frustrated 2-leg spin-1/2 ladders with skewed rungs
Geetanjali Giri, Dayasindhu Dey, Manoranjan Kumar +2
The quantum phases of 2-leg spin-1/2 ladders with skewed rungs are obtained using exact diagonalization of systems with up to 26 spins and by density matrix renormalization group c…
Density matrix renormalization group (DMRG) for cyclic and centrosymmetric linear chains
Manoranjan Kumar, Dayasindhu Dey, Aslam Parvej +2
The density matrix renormalization group (DMRG) method generates the low-energy states of linear systems of sites with a few degrees of freedom at each site by starting with a…
Correlated Electronic Properties of Some Graphene Nanoribbons: A DMRG Study
V. M. L. Durga Prasad Goli, Suryoday Prodhan, Sumit Mazumdar +1
The significant electron-electron interactions that characterize the π-electrons of graphene nanoribbons (GNRs) necessitate going beyond one-electron tight-binding description. Exi…
Efficient Density Matrix Renormalization Group algorithm to study Y-Junctions with integer and half-integer spin
Manoranjan Kumar, Aslam Parvej, Simil Thomas +2
An efficient density matrix renormalization group (DMRG) algorithm is presented and applied to Y-junctions, systems with three arms of sites that meet at a central site. The ac…
An Exact Solution of the PPP Model for Correlated Electronic States of Tetracene and Substituted Tetracene
Y. Anusooya Pati, S. Ramasesha
Tetracene is an important conjugated molecule for device applications. We have used the diagrammatic valence bond method to obtain the desired states, in a Hilbert space of about 4…
Studies on a frustrated Heisenberg spin chain with alternating ferromagnetic and antiferromagnetic exchanges
Shaon Sahoo, V. M. L. Durga Prasad Goli, Diptiman Sen +1
We study Heisenberg spin-1/2 and spin-1 chains with alternating ferromagnetic () and antiferromagnetic () nearest-neighbor interactions and a ferromagnetic next-neare…
Quantum phases of dimerized and frustrated Heisenberg spin chains with s = 1/2, 1 and 3/2: an entanglement entropy and fidelity study
V. M. L. Durga Prasad Goli, Shaon Sahoo, S. Ramasesha +1
We study here different regions in phase diagrams of the spin-1/2, spin-1 and spin-3/2 one dimensional antiferromagnetic Heisenberg systems with frustration (next-nearest-neighbor…
Density matrix renormalization group algorithm for Bethe lattices of spin 1/2 or 1 sites with Heisenberg antiferromagnetic exchange
Manoranjan Kumar, S. Ramasesha, Zoltan G. Soos
An efficient density matrix renormalization group (DMRG) algorithm is presented for the Bethe lattice with connectivity and antiferromagnetic exchange between nearest neigh…
Fused Azulenes: Possible Organic Multiferroics
Simil Thomas, S. Ramasesha, Karen Hallberg +1
We present compelling theoretical results showing that fused azulene molecules are strong candidates for exhibiting room temperature multiferroic behavior, i.e., having both, ferro…
Real-time density matrix renormalization group dynamics of spin and charge transport in push-pull polyenes and related systems
Tirthankar Dutta, S. Ramasesha
In this paper we investigate the effect of terminal substituents on the dynamics of spin and charge transport in donor-acceptor substituted polyenes () chains, also k…
1:1 alkali-TCNQ salts and the bond order wave (BOW) phase of half-filled linear Hubbard-type models
Z G. Soos, M. Kumar, S. Ramasesha +1
The bond order wave (BOW) phase of half-filled linear Hubbard-type models is narrow and difficult to characterize aside from a few ground state properties. The BOW phase of a frust…
Bond-order wave phase, spin solitons and thermodynamics of a frustrated linear spin-1/2 Heisenberg antiferromagnet
Manoranjan Kumar, S. Ramasesha, Z. G. Soos
The linear spin-1/2 Heisenberg antiferromagnet with exchanges , between first and second neighbors has a bond-order wave (BOW) phase that starts at the fluid-dimer trans…
Real Time Dynamics of Hole Propagation in Strongly Correlated Conjugated Molecular Chains: A time-dependent DMRG Study
Tirthankar Dutta, S. Ramasesha
In this paper, we address the role of electron-electron interactions on the velocities of spin and charge transport in one-dimensional systems typified by conjugated polymers. We e…
Double Time Window Targeting Technique: Real time DMRG dynamics in the PPP model
Tirthankar Dutta, S. Ramasesha
We present a generalized adaptive time-dependent density matrix renormalization group (DMRG) scheme, called the {\it double time window targeting} (DTWT) technique, which gives acc…
Modified DMRG algorithm for the zigzag spin-1/2 chain with frustrated antiferromagnetic exchange: Comparison with field theory at large
Manoranjan Kumar, Zoltan G. Soos, Diptiman Sen +1
A modified density matrix renormalization group (DMRG) algorithm is applied to the zigzag spin-1/2 chain with frustrated antiferromagnetic exchange , between first and s…
Quantum interference in coherent molecular conductance
Julian Rincon, K. Hallberg, S. Ramasesha
Coherent electronic transport through individual molecules is crucially sensitive to quantum interference. Using exact diagonalization techniques, we investigate the zero-bias and…