182 citations · 1.3k across the 35 of their papers we have counts for
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Large scale numerical investigation of excited states in poly(phenylene)
Robert J. Bursill, W. Barford
A density matrix renormalisation group scheme is developed, allowing for the first time essentially exact numerical solutions for the important excited states of a realistic semi-e…
The low-lying excitations of polydiacetylene
Alan Race, W. Barford, Robert J. Bursill
The Pariser-Parr-Pople Hamiltonian is used to calculate and identify the nature of the low-lying vertical transition energies of polydiacetylene. The model is solved using the dens…
Excited states of linear polyenes
William Barford, Robert J. Bursill, Mikhail Yu Lavrentiev
We present density matrix renormalisation group calculations of the Pariser- Parr-Pople-Peierls model of linear polyenes within the adiabatic approximation. We calculate the vertic…
Comment on ``Density-matrix renormalization-group method for excited states''
Robert J. Bursill
In a Physical Review B paper Chandross and Hicks claim that an analysis of the density-density correlation function in the dimerised Hubbard model of polyacetylene indicates that t…
Electron-lattice relaxation, and soliton structures and their interactions in polyenes
Robert J. Bursill, William Barford
Density matrix renormalisation group calculations of a suitably parametrised model of long polyenes (polyacetylene oligomers), which incorporates both long range Coulomb interactio…
A theoretical investigation of the low lying electronic structure of poly(p-phenylene vinylene)
Mikhail Yu. Lavrentiev, William Barford, Simon J. Martin +2
The two-state molecular orbital model of the one-dimensional phenyl-based semiconductors is applied to poly(p-phenylene vinylene). The energies of the low-lying excited states are…
Molecular Orbital Models of Benzene, Biphenyl and the Oligophenylenes
R. J. Bursill, W. Barford, H. Daly
A two state (2-MO) model for the low-lying long axis-polarised excitations of poly(p-phenylene) oligomers and polymers is developed. First we derive such a model from the underlyin…
Phase diagram of a Heisenberg spin-Peierls model with quantum phonons
Robert J. Bursill, Ross H. McKenzie, Chris J. Hamer
Using a new version of the density-matrix renormalization group we determine the phase diagram of a model of an antiferromagnetic Heisenberg spin chain where the spins interact wit…
Identification of excitons in conjugated polymers: a density matrix renormalisation group study
M. Boman, R. J. Bursill
This work addresses the question of whether low-lying excitations in conjugated polymers are comprised of free charge-carriers or excitons. States are characterised as bound or unb…
DMRG Calculations of the Low-lying Excitations and Nonlinear Optical Properties of poly(para-phenylene)
W. Barford, R. J. Bursill, M. Yu. Lavrentiev
The two state molecular orbital (2-MO) model of the phenyl based semiconductors is used to calculate the low-lying spectra of the Ag and Bu states of poly(para-phenylene) (PPP). Th…
Phase diagram of the one-dimensional Holstein model of spinless fermions
R. J. Bursill, R. H. McKenzie, C. J. Hamer
The one-dimensional Holstein model of spinless fermions interacting with dispersionless phonons is studied using a new variant of the density matrix renormalisation group. By exami…
Density matrix renormalisation group for a quantum spin chain at non-zero temperature
R. J. Bursill, T. Xiang, G. A. Gehring
We apply a recent adaptation of White's density matrix renormalisation group (DMRG) method to a simple quantum spin model, the dimerised chain, in order to assess the applicab…
Applications of the density matrix renormalisation group to problems in magnetism
G. A. Gehring, R. J. Bursill, T. Xiang
We review White's density matrix renormalisation group method, an increasingly popular method for the solution of low dimensional quantum Hamiltonians. We describe some application…
The density matrix renormalisation group and critical phenomena
R. J. Bursill, F. Gode
We adapt White's density matrix renormalisation group (DMRG) to the direct study of critical phenomena. We use the DMRG to generate transformations in the space of coupling constan…
Numerical and approximate analytical results for the frustrated spin-1/2 quantum spin chain
R. J. Bursill, G. A. Gehring, D. J. J. Farnell +3
We study the frustrated phase of the quantum spin- system with nearest-neighbour and next-nearest-neighbour isotropic exchange known as the Majumdar-Ghosh Hami…
One Dimensional Continuum Falicov-Kimball Model in the Strongly Correlated Limit
R. J. Bursill
In this paper we study the thermodynamics of the one dimensional continuum analogue of the Falicov-Kimball model in the strongly correlated limit using a method developed by Salsbu…
Density matrix renormalisation group study of the correlation function of the bilinear-biquadratic spin-1 chain
R. J. Bursill, T. Xiang, G. A. Gehring
Using the recently developed density matrix renormalization group approach, we study the correlation function of the spin-1 chain with quadratic and biquadratic interactions. This…