2018/11/30 by Dario Tamascelli, Andrea Smirne, J. Lim +4 · 2 citations
Mathematics · Physics and Astronomy · #Advanced Thermodynamics and Statistical Mechanics #Computer science #Density matrix #Density matrix renormalization group #Mathematics #Mesoscopic physics #Open quantum system #Open system (computing) #Physics #Quantum #Quantum many-body systems #Quantum mechanics #Quantum simulator #Quantum system #Quantum thermodynamics #Scaling #Spectroscopy and Quantum Chemical Studies #Speedup #Statistical physics #Thermal #Thermodynamics #quant-ph
paper · pdf · doi:10.1103/physrevlett.123.090402
published as Phys. Rev. Lett. 123, 090402 (2019) · 5+5 pages, close to published version
openalex publication_date 2019/08/27 · arxiv created 2019/08/30 · arxiv updated 2019/09/02 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Chain-mapping techniques in combination with the time-dependent density matrix renormalization group are a powerful tool for the simulation of open-system quantum dynamics. For finite-temperature environments, however, this approach suffers from an unfavorable algorithmic scaling with increasing temperature. We prove that the system dynamics under thermal environments can be nonperturbatively described by temperature-dependent system-environmental couplings with the initial environment state being in its pure vacuum state, instead of a mixed thermal state. As a consequence, as long as the initial system state is pure, the global system-environment state remains pure at all times. The resulting speed-up and relaxed memory requirements of this approach enable the efficient simulation of open quantum systems interacting with highly structured environments in any temperature range, with applications extending from quantum thermodynamics to quantum effects in mesoscopic systems.