Z. Soos

activity

20012024

most citedElectronic polarization at surfaces and thin films of organic molecular crystals: PTCDA

279 citations · 788 across the 35 of their papers we have counts for

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27 papers · 1 filter

cond-mat.str-el2024

Spin-1/2 string correlations and singlet-triplet gaps of frustrated ladders with ferromagnetic (F) legs and alternate F and AF rungs

Monalisa Chatterjee, Manoranjan Kumar, Zoltán G. Soos

The frustrated ladder with alternate ferromagnetic(F) exchange $- J_{F}$ and AF exchange $J_{A}$ to first neighbors and F exchange $- J_{L}$ to second neighbors is studied by exact diagona…

cond-mat.str-el2023★ 1 cited

Quantum Phase Transitions in Skewed Ladder Systems

Sambunath Das, Dayasindhu Dey, Rajamani Raghunathan +3

In this brief review, we introduce a new spin ladder system called skewed spin ladders and discuss the exotic quantum phases of this system. The spin ladders studied are the 5/7, 3…

cond-mat.str-el2023★ 1 cited

Singlet quantum phases and magnetization of the frustrated spin-1/2 ladder with ferromagnetic (F) exchange in legs and alternating F-AF exchange in rungs

Monalisa Chatterjee, Manoranjan Kumar, Zoltán G. Soos

The magnetization $M (h)$ is used to identify three singlet quantum phases of the ladder with isotropic exchange interactions. The Dimer phase with frustrated F exchanges in rungs a…

cond-mat.str-el2022★ 4 cited

Spin Peierls transition of $J_{1} - J_{2}$ and extended models with ferromagnetic $J_{1}$ .Sublattice dimerization and thermodynamics of zigzag chains in $β$ -TeVO $_{4}$

Manodip Routh, Sudip Kumar Saha, Manoranjan Kumar +1

The spin $- 1/2$ chain with ferromagnetic exchange $J_{1} < 0$ between first neighbors and antiferromagnetic $J_{2} > 0$ between second neighbors supports two spin-Peierls (SP) instabili…

cond-mat.str-el2021★ 3 cited

Low temperature thermodynamics of the antiferromagnetic $J_{1} - J_{2}$ model: Entropy, critical points and spin gap

Sudip Kumar Saha, Manodip Routh, Manoranjan Kumar +1

The antiferromagnetic $J_{1} - J_{2}$ model is a spin-1/2 chain with isotropic exchange $J_{1} > 0$ between first neighbors and $J_{2} = α J_{1}$ between second neighbors. The model supports bo…

cond-mat.str-el2021★ 3 cited

Density matrix renormalization group approach to the low temperature thermodynamics of correlated 1D fermionic models

Sudip Kumar Saha, Debasmita Maiti, Manoranjan Kumar +1

The low temperature thermodynamics of correlated 1D fermionic models with spin and charge degrees of freedom is obtained by exact diagonalization (ED) of small systems and followed…

cond-mat.str-el2020★ 1 cited

Bond-bond correlations, gap relations and thermodynamics of spin- $1/2$ chains with spin-Peierls transitions and bond-order-wave phases

Sudip Kumar Saha, Manoranjan Kumar, Zoltán G. Soos

The spin- $1/2$ chain with antiferromagnetic exchange $J_{1}$ and $J_{2} = α J_{1}$ between first and second neighbors, respectively, has both gapless and gapped ( $Δ (α) > 0$ ) quantum phase…

cond-mat.str-el2020★ 5 cited

Intriguing relaxor ferroelectricity in a polar CT crystal at the neutral-ionic interface

J. K. H. Fischer, G. D'Avino, M. Masino +4

We investigated the mixed-stack charge-transfer crystal, N,N'-dimethylphenazine-TCNQ (M $_{2}$ P-TCNQ), which is polar at room temperature and just at the neutral-to-ionic interface (i…

cond-mat.str-el2020★ 15 cited

Modeling the spin-Peierls transition of spin- $1/2$ chains with correlated states: $J_{1} - J_{2}$ model, CuGeO $_{3}$ and TTF-CuS $_{4}$ C $_{4}$ (CF $_{3}$ ) $_{4}$

Sudip Kumar Saha, Monalisa Singh Roy, Manoranjan Kumar +1

The spin-Peierls transition at $T_{S P}$ of spin- $1/2$ chains with isotropic exchange interactions has previously been modeled as correlated for $T > T_{S P}$ and mean field for $T <…

cond-mat.str-el2019

Spin-Peierls transition of the dimer phase of the $J_{1} - J_{2}$ model: Energy cusp and CuGeO $_{3}$ thermodynamics

Sudip Kumar Saha, Manoranjan Kumar, Zoltán G. Soos

The spin-Peierls transition is modeled in the dimer phase of the spin- $1/2$ chain with exchanges $J_{1}$ , $J_{2} = α J_{1}$ between first and second neighbors. The degenerate ground state…

cond-mat.str-el2019

Hybrid ED/DMRG approach to the thermodynamics of 1D quantum models

Sudip Kumar Saha, Dayasindhu Dey, Manoranjan Kumar +1

Exact diagonalization (ED) of small model systems gives the thermodynamics of spin chains or quantum cell models at high temperature $T$ . Density matrix renormalization group (DMRG…

cond-mat.str-el2018★ 9 cited

Spin-specific heat determination of the ratio of competing first- and second-neighbor exchange interactions in frustrated spin- $\frac{1}{2}$ chains

Dayasindhu Dey, Manoranjan Kumar, Siân E. Dutton +2

The magnetic susceptibility $χ (T)$ of spin-1/2 chains is widely used to quantify exchange interactions, even though $χ (T)$ is similar for different combinations of ferromagnetic $J…

cond-mat.str-el2017★ 26 cited

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…

cond-mat.str-el2016

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 $N$ sites with a few degrees of freedom at each site by starting with a…

cond-mat.str-el2016★ 7 cited

Boundary-induced spin density waves in linear Heisenberg antiferromagnetic spin chains with $S \geq 1$

Dayasindhu Dey, Manoranjan Kumar, Zoltán G. Soos

Linear Heisenberg antiferromagnets (HAFs) are chains of spin- $S$ sites with isotropic exchange $J$ between neighbors. Open and periodic boundary conditions return the same ground s…

cond-mat.str-el2016★ 31 cited

Numerical study of incommensurate and decoupled phases of spin-1/2 chains with isotropic exchange J1, J2 between first and second neighbors

Zoltán G. Soos, Aslam Parvej, Manoranjan Kumar

The spin-1/2 chain with isotropic exchange J1, J2 > 0 between first and second neighbors is frustrated for either sign of J1 and has a singlet ground state (GS) for J1/J2 $\geq - 4$ …

cond-mat.str-el2015

Level crossing, spin structure factor and quantum phases of the frustrated spin-1/2 chain with first and second neighbor exchange

Manoranjan Kumar, Aslam Parvej, Zoltán G. Soos

The spin-1/2 chain with isotropic Heisenberg exchange $J_{1}$ , $J_{2} > 0$ between first and second neighbors is frustrated for either sign of J1. Its quantum phase diagram has critica…

cond-mat.str-el2012★ 16 cited

Spin parity and broken symmetry in finite spin-1/2 chains with frustrated exchange: quantum transition from high to low spin

Manoranjan Kumar, Zoltán G. Soos

Exact diagonalization of finite spin-1/2 chains with periodic boundary conditions is applied to the ground state (gs) of chains with ferromagnetic (F) exchange $J_{1} < 0$ between fir…

cond-mat.str-el2011★ 19 cited

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 $Z = 3$ and antiferromagnetic exchange between nearest neigh…

cond-mat.str-el2011★ 10 cited

Bond order wave (BOW) phase of the extended Hubbard model: Electronic solitons, paramagnetism, coupling to Peierls and Holstein phonons

Manoranjan Kumar, Zolt'an G. Soos

The bond order wave (BOW) phase of the extended Hubbard model (EHM) in one dimension (1D) is characterized at intermediate correlation $U = 4 t$ by exact treatment of $N$ -site syste…

cond-mat.str-el2010★ 3 cited

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…

cond-mat.str-el2010★ 36 cited

Modified DMRG algorithm for the zigzag spin-1/2 chain with frustrated antiferromagnetic exchange: Comparison with field theory at large $J_{2} / J_{1}$

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 $J_{1}$ , $J_{2}$ between first and s…

cond-mat.str-el2008★ 41 cited

Tuning the bond order wave (BOW) phase of half-filled extended Hubbard models

Manoranjan Kumar, S. Ramasesha, Z. G. Soos

Theoretical and computational studies of the quantum phase diagram of the one-dimensional half-filled extended Hubbard model (EHM) indicate a narrow bond order wave (BOW) phase wit…

cond-mat.str-el2007★ 21 cited

Anomalous dispersion of optical phonons at the neutral-ionic transition: Evidence from diffuse X-ray scattering

Gabriele D'Avino, Alberto Girlando, Anna Painelli +2

Diffuse X-ray data for mixed stack organic charge-transfer crystals approaching the neutral-ionic phase transition can be quantitatively explained as due to the softening of the op…