PMID- 32668942
OWN - NLM
STAT- MEDLINE
DCOM- 20210113
LR  - 20210113
IS  - 1089-7690 (Electronic)
IS  - 0021-9606 (Linking)
VI  - 153
IP  - 2
DP  - 2020 Jul 14
TI  - Numerically "exact" approach to open quantum dynamics: The hierarchical equations 
      of motion (HEOM).
PG  - 020901
LID - 10.1063/5.0011599 [doi]
AB  - An open quantum system refers to a system that is further coupled to a bath 
      system consisting of surrounding radiation fields, atoms, molecules, or proteins. 
      The bath system is typically modeled by an infinite number of harmonic 
      oscillators. This system-bath model can describe the time-irreversible dynamics 
      through which the system evolves toward a thermal equilibrium state at finite 
      temperature. In nuclear magnetic resonance and atomic spectroscopy, dynamics can 
      be studied easily by using simple quantum master equations under the assumption 
      that the system-bath interaction is weak (perturbative approximation) and the 
      bath fluctuations are very fast (Markovian approximation). However, such 
      approximations cannot be applied in chemical physics and biochemical physics 
      problems, where environmental materials are complex and strongly coupled with 
      environments. The hierarchical equations of motion (HEOM) can describe the 
      numerically "exact" dynamics of a reduced system under nonperturbative and 
      non-Markovian system-bath interactions, which has been verified on the basis of 
      exact analytical solutions (non-Markovian tests) with any desired numerical 
      accuracy. The HEOM theory has been used to treat systems of practical interest, 
      in particular, to account for various linear and nonlinear spectra in molecular 
      and solid state materials, to evaluate charge and exciton transfer rates in 
      biological systems, to simulate resonant tunneling and quantum ratchet processes 
      in nanodevices, and to explore quantum entanglement states in quantum information 
      theories. This article presents an overview of the HEOM theory, focusing on its 
      theoretical background and applications, to help further the development of the 
      study of open quantum dynamics.
FAU - Tanimura, Yoshitaka
AU  - Tanimura Y
AUID- ORCID: 000000027913054X
AD  - Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 
      606-8502, Japan.
LA  - eng
PT  - Journal Article
PL  - United States
TA  - J Chem Phys
JT  - The Journal of chemical physics
JID - 0375360
SB  - IM
MH  - Models, Chemical
MH  - *Motion
MH  - *Quantum Theory
EDAT- 2020/07/17 06:00
MHDA- 2021/01/14 06:00
CRDT- 2020/07/17 06:00
PHST- 2020/07/17 06:00 [entrez]
PHST- 2020/07/17 06:00 [pubmed]
PHST- 2021/01/14 06:00 [medline]
AID - 10.1063/5.0011599 [doi]
PST - ppublish
SO  - J Chem Phys. 2020 Jul 14;153(2):020901. doi: 10.1063/5.0011599.