2014/05/31 by Daniel Stanek, Carsten Raas, Götz S. Uhrig
Computer Science · Physics and Astronomy · #Classical mechanics #Condensed matter physics #Density matrix #Density matrix renormalization group #Gaussian #Magnetic field #Physics #Quantum #Quantum Information and Cryptography #Quantum and electron transport phenomena #Quantum many-body systems #Quantum mechanics #Renormalization #Semiclassical physics #Spin (aerodynamics) #Spins #cond-mat.mes-hall #quant-ph
paper · pdf · doi:10.1103/physrevb.90.064301
published as Physical Review B 90, 064301 (2014) · 13 pages, 9 figures
openalex publication_date 2014/08/04 · arxiv created 2014/08/12 · arxiv updated 2014/08/13 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We discuss the semiclassical and classical character of the dynamics of a single spin 1/2 coupled to a bath of noninteracting spins 1/2. On the semiclassical level, we extend our previous approach presented in D. Stanek, C. Raas, and G. S. Uhrig, Phys. Rev. B 88, 155305 (2013) by the explicit consideration of the conservation of the total spin. On the classical level, we compare the results of the classical equations of motions in absence and presence of an external field to the full quantum result obtained by density-matrix renormalization (DMRG). We show that for large bath sizes and not too low magnetic field the classical dynamics, averaged over Gaussian distributed initial spin vectors, agrees quantitatively with the quantum-mechanical one. This observation paves the way for an efficient approach for certain parameter regimes.