Analytic response theory for the density matrix renormalisation group
نویسندگان
چکیده
We propose an analytic response theory for the density matrix renormalisation group whereby response properties correspond to analytic derivatives of density matrix renormalisation group observables with respect to the applied perturbations. Both static and frequency-dependent response theories are formulated and implemented. We evaluate our pilot implementation by calculating static and frequencydependent polarisabilities of short oligo-di-acetylenes. The analytic response theory is competitive with dynamical density matrix renormalisation group methods and yields significantly improved accuracies when using a small number of density matrix renormalisation group states. Strengths and weaknesses of the analytic approach are discussed.
منابع مشابه
Analytic response theory for the density matrix renormalization group.
We propose an analytic response theory for the density matrix renormalization group, whereby response properties correspond to analytic derivatives of density matrix renormalization group observables with respect to the applied perturbations. Both static and frequency-dependent response theories are formulated and implemented. We evaluate our pilot implementation by calculating static and frequ...
متن کاملFlavour Changing Neutral Current Effects from Flavour Dependent Supergravity Couplings
We investigate the impact on low energy flavour mixing phenomena of the renormalisation group running of parameters in supersymmetric theories. We have explicitly chosen flavour dependent supergravity couplings. The renormalisation group equations are displayed in general matrix form. We work in a scale dependent basis such that the hierarchy in the quark masses can be more easily utilised. Sim...
متن کاملThe density matrix renormalisation group and critical phenomena
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 constants. We postulate that a study of density matrix eigenvalues leads to a natural identification of renormalised blocks, operators and Hamiltonians. We apply the scheme to the phase transition in the anisotropic spin-1/2...
متن کاملDensity-matrix renormalisation group approach to quantum impurity problems
A dynamic density-matrix renormalisation group approach to the spectral properties of quantum impurity problems is presented. The method is demonstrated on the spectral density of the flat-band symmetric single-impurity Anderson model. We show that this approach provides the impurity spectral density for all frequencies and coupling strengths. In particular, Hubbard satellites at high energy ca...
متن کاملApplications of the density matrix renormalisation group to problems in magnetism
The application of real space renormalisation group methods to quantum lattice models has become a topic of great interest following the development of the Density Matrix Renormalisation Group (DMRG) by White. This method has been used to find the ground and low-lying excited state energies and wave functions of quantum spin models in which the form of the ground state is not clear, for instanc...
متن کامل