Adaptive broadening to improve spectral resolution in the numerical renormalization group

Abstract

We propose an adaptive scheme of broadening the discrete spectral data from numerical renormalization group (NRG) calculations to improve the resolution of dynamical properties at finite energies. While the conventional scheme overbroadens narrow features at large frequency by broadening discrete weights with constant width in log-frequency, our scheme broadens each discrete contribution individually based on its sensitivity to a z-shift in the logarithmic discretization intervals. We demonstrate that the adaptive broadening better resolves various features in non-interacting and interacting models at comparable computational cost. The resolution enhancement is more significant for coarser discretization as typically required in multi-band calculations. At low frequency below the energy scale of temperature, the discrete NRG data necessarily needs to be broadened on a linear scale. Here we provide a method that minimizes transition artefacts in between these broadening kernels.

References in corpus (7)

• The numerical renormalization group method for quantum impurity systems
• Real-time dynamics in Quantum Impurity Systems: A Time-dependent Numerical Renormalization Group Approach
• Sum-rule Conserving Spectral Functions from the Numerical Renormalization Group
• Energy resolution and discretization artefacts in the numerical renormalization group
• Spin Precession and Real Time Dynamics in the Kondo Model: A Time-Dependent Numerical Renormalization-Group Study
• DMFT+NRG study of spin-orbital separation in a three-band Hund's metal
• Optimal broadening of finite energy spectra in the numerical renormalization group: application to dissipative dynamics in two-level systems

Cited by in corpus (38)

• Strongly correlated materials from a numerical renormalization group perspective: How the Fermi-liquid state of Sr${}_2$RuO${}_4$ emerges
• Multipoint correlation functions: spectral representation and numerical evaluation
• Orbital differentiation in Hund metals
• Doublon-holon origin of the subpeaks at the Hubbard band edges
• Is the orbital-selective Mott phase stable against interorbital hopping?
• At which magnetic field, exactly, does the Kondo resonance begin to split? A Fermi liquid description of the low-energy properties of the Anderson model
• Mott quantum criticality in the one-band Hubbard model: Dynamical mean-field theory, power-law spectra, and scaling
• Manipulating Non-Abelian Anyons in a Chiral Multichannel Kondo Model
• Uncovering Non-Fermi-Liquid Behavior in Hund Metals: Conformal Field Theory Analysis of an SU(2)$\times$SU(3) Spin-Orbital Kondo Model
• Filling-driven Mott transition in SU(N) Hubbard models
• Complex Time Evolution in Tensor Networks
• Automatic Differentiable Numerical Renormalization Group
• Equilibrium Quantum Impurity Problems via Matrix Product State Encoding of the Retarded Action
• Real-frequency quantum field theory applied to the single-impurity Anderson model
• Real-time Impurity Solver Using Grassmann Time-Evolving Matrix Product Operators
• Solving quantum impurity problems on the L-shaped Kadanoff-Baym contour
• LiV2O4: Hund-Assisted Orbital-Selective Mottness
• Dynamical correlation functions from complex time evolution
• Symmetric improved estimators for multipoint vertex functions
• Stabilizing the calculation of the self-energy in dynamical mean-field theory using constrained residual minimization
• Semi-group influence matrices for non-equilibrium quantum impurity models
• Low-energy perspective on two-orbital Hund metals and the case of LaNiO2
• Chiral numerical renormalization group
• Fermi-Liquid $T^2$ Resistivity: Dynamical Mean-Field Theory Meets Experiment
• Non-Hermitian Numerical Renormalization Group: Solution of the non-Hermitian Kondo model
• Vacancy-induced tunable Kondo effect in twisted bilayer graphene
• Testing the parquet equations and the U(1) Ward identity for real-frequency correlation functions from the multipoint numerical renormalization group
• Low-temperature transport in high-conductivity correlated metals: a density-functional plus dynamical mean-field study of cubic perovskites
• The finite-difference parquet method: Enhanced electron-paramagnon scattering opens a pseudogap
• Infinite Grassmann time-evolving matrix product operator method for zero-temperature equilibrium quantum impurity problems
• Oscillate and Renormalize: Fast Phonons Reshape the Kondo Effect in Flat Band Systems
• Infinite Grassmann time-evolving matrix product operators for quantum impurity problems after a quench
• Mott Transition and Volume Law Entanglement with Neural Quantum States
• Relevance of Anisotropy in the Kondo Effect: Lessons From the Symplectic Case
• Scalable tensor network algorithm for quantum impurity problems
• Improved estimator for numerical renormalization group calculations of the self-energy
• Computing local multipoint correlators using the numerical renormalization group
• Compressing local vertex functions from the multipoint numerical renormalization group using quantics tensor cross interpolation