Non-perturbative Many-Body Treatment of Molecular Magnets
arXiv:2303.09010 · doi:10.1063/5.0150706
Abstract
Molecular magnets have received significant attention because of their potential applications in quantum information and quantum computing. A delicate balance of electron correlation, spin-orbit coupling (SOC), ligand field splitting, and other effects produces a persistent magnetic moment within each molecular magnet unit. The discovery and design of molecular magnets with improved functionalities would be greatly aided by accurate computations. However, the competition among the different effects poses a challenge for theoretical treatments. Electron correlation plays a central role, since d-, or f-element ions, which provide the magnetic states in molecular magnets, often require explicit many-body treatments. SOC, which expands the dimensionality of the Hilbert space, can also lead to non-perturbative effects in the presence of strong interaction. Furthermore, molecular magnets are large, with tens of atoms in even the smallest systems. We show how an treatment of molecular magnets can be achieved with auxiliary-field quantum Monte Carlo (AFQMC), in which electron correlation, SOC, and material specificity are included accurately and on an equal footing. The approach is demonstrated by an application to compute the zero-field splitting of a locally-linear Co complex.
arXiv comment22 pages, 3 figures
References in corpus (25)
- Heat-bath Configuration Interaction: An efficient selected CI algorithm inspired by heat-bath sampling
- Semistochastic Heat-bath Configuration Interaction method: selected configuration interaction with semistochastic perturbation theory
- Operating Quantum States in Single Magnetic Molecules: Implementation of Grover's Quantum Algorithm
- Quantum Monte Carlo method using phase-free random walks with Slater determinants
- Optically addressable molecular spins for quantum information processing
- Ab initio computations of molecular systems by the auxiliary-field quantum Monte Carlo method
- Auxiliary-field quantum Monte Carlo calculations of molecular systems with a Gaussian basis
- On Achieving High Accuracy in Quantum Chemical Calculations of 3d Transition Metal Systems: A Comparison of Auxiliary-Field Quantum Monte Carlo with Coupled Cluster, Density Functional Theory, and Experiment for Diatomic Molecules
- Direct comparison of many-body methods for realistic electronic Hamiltonians
- Quantum Monte Carlo method for the ground state of many-boson systems
- Some Recent Developments in Auxiliary-Field Quantum Monte Carlo for Real Materials
- Excited state calculations using phaseless auxiliary-field quantum Monte Carlo: potential energy curves of low lying C2 singlet states
- One-step treatment of spin-orbit coupling and electron correlation in large active spaces
- Assessing weak hydrogen binding on Ca+ centers: An accurate many-body study with large basis sets
- Landau-Zener tunneling of a single Tb3+ magnetic moment allowing the electronic read-out of a nuclear spin
- Phaseless Auxiliary-Field Quantum Monte Carlo on Graphical Processing Units
- Computation of ground-state properties in molecular systems: back-propagation with auxiliary-field quantum Monte Carlo
- Chemical Transformations Approaching Chemical Accuracy via Correlated Sampling in Auxiliary-Field Quantum Monte Carlo
- Predicting Ligand-Dissociation Energies of 3d Coordination Complexes with Auxiliary-Field Quantum Monte Carlo
- Excited state calculations in solids by auxiliary-field quantum Monte Carlo
- Accelerating Auxiliary-Field Quantum Monte Carlo Simulations of Solids with Graphical Processing Unit
- Frozen-orbital and downfolding calculations with auxiliary-field quantum Monte Carlo
- Local embedding and effective downfolding in the auxiliary-field quantum Monte Carlo method
- Computation of forces and stresses in solids: Towards accurate structural optimization with auxiliary-field quantum Monte Carlo
- Ab initio Calculations in Atoms, Molecules, and Solids, Treating Spin-Orbit Coupling and Electron Interaction on Equal Footing