Spin precession and real-time dynamics in the Kondo model:Time-dependent numerical renormalization-group study
By F. Anders, A. Schiller. 2006
180 citations recorded by the source corpus.
A detailed derivation of the recently proposed time-dependent numerical renormalization-group (TD-NRG) approach to nonequilibrium dynamics in quantum-impurity systems is presented. We demonstrate that the method is suitable for fermionic as well as bosonic baths. Comparisons with exact analytical results for the charge relaxation in the resonant-level model and for dephasing in the spin-boson model establish the accuracy of the method. The real-time dynamics of a single spin coupled to each type of bath is investigated. We use the TD-NRG to calculate the spin relaxation and spin precession of a single Kondo impurity. The short- and long-time dynamics are studied as a function of temperature in the ferromagnetic and antiferromagnetic regimes. The short-time dynamics agrees very well with analytical results obtained at second order in the exchange coupling $J$. In the ferromagnetic regime, the transient spin decay is described by the scaling variable $x=2{\ensuremath{\rho}}_{F}\ensuremath{\mid}J(T)\ensuremath{\mid}Tt$. In the antiferromagnetic regime, the long-time decay is governed for $Tl{T}_{K}$ by the Kondo time scale $1∕{T}_{K}$. Here ${\ensuremath{\rho}}_{F}$ is the conduction-electron density of states, ${T}_{K}$ is the Kondo temperature, and $J(T)$ is the effective exchange coupling at temperature $T$. Results for spin precession are obtained by rotating the external magnetic field from the $x$ axis to the $z$ axis.
Subfields: Atomic and Molecular Physics, and Optics, Condensed Matter Physics
View Paper: https://www.semanticscholar.org/paper/5b53dafa06b7132070282f320b55fe3f4d520001
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In Atomic and Molecular Physics, and Optics
In Condensed Matter Physics
Citations in the corpus
- Numerical renormalization group method for quantum impurity systems (2007, methodology): “Within this approach the timedependent transient dynamics of a number of models has been investigated, including the Anderson and resonant level models (Anders and Schiller, 2005), the Kondo model (Anders and Schiller, 2006) and the sub-ohmic spin-boson model (Anders et al., 2007).”