Non-perturbative effects and indirect exchange interaction between quantum impurities on metallic (111) surfaces
arXiv:1611.06883 · doi:10.1103/PhysRevB.95.235416
Abstract
The (111) surface of noble metals is usually treated as an isolated two dimensional (2D) triangular lattice completely decoupled from the bulk. However, unlike topological insulators, other bulk bands cross the Fermi level. We here introduce an effective tight-binding model that accurately reproduces results from first principles calculations, accounting for both surface and bulk states. We numerically solve the many-body problem of two quantum impurities sitting on the surface by means of the density matrix renormalization group. By performing simulations in a star geometry, we are able to study the non-perturbative problem in the thermodynamic limit with machine precision accuracy. We find that there is a non-trivial competition between Kondo and RKKY physics and as a consequence, ferromagnetism is never developed, except at short distances. The bulk introduces a variation in the period of the RKKY interactions, and therefore the problem departs considerably from the simpler 2D case. In addition, screening, and the magnitude of the effective indirect exchange is enhanced by the contributions from the bulk states.
References in corpus (15)
- Exchange interaction between single magnetic adatoms
- Numerical Renormalization Group for Quantum Impurities in a Bosonic Bath
- Atomic spin chain realization of a model for quantum criticality
- Spin wave imaging in atomically designed nanomagnets
- Solving nonequilibrium dynamical mean-field theory using matrix product states
- Shockley model description of surface states in topological insulators
- Metallic, Magnetic and Molecular Nanocontacts
- First-principles Calculation of the Single Impurity Surface Kondo Resonance
- Kondo versus indirect exchange: the role of the lattice and the actual range of RKKY interactions in real materials
- Competition between Kondo effect and RKKY physics in graphene magnetism
- Lanczos transformation for quantum impurity problems in d-dimensional lattices: application to graphene nanoribbons
- Block Lanczos density-matrix renormalization group method for general Anderson impurity models: Application to magnetic impurity problems in graphene
- Kondo Effect and Surface-State Electrons
- Microscopic Theory of the Single Impurity Surface Kondo Resonance
- Exchange interaction between magnetic adatoms on surfaces of noble metals