PMID- 29935503
OWN - NLM
STAT- PubMed-not-MEDLINE
DCOM- 20180628
LR  - 20180628
IS  - 1089-7690 (Electronic)
IS  - 0021-9606 (Linking)
VI  - 148
IP  - 23
DP  - 2018 Jun 21
TI  - On the exact truncation tier of fermionic hierarchical equations of motion.
PG  - 234108
LID - 10.1063/1.5034776 [doi]
AB  - The hierarchical equations of motion (HEOM) theory is in principle exact for 
      describing the dissipative dynamics of quantum systems linearly coupled to 
      Gaussian environments. In practice, the hierarchy needs to be truncated at a 
      finite tier. We demonstrate that, for general systems described by the fermionic 
      HEOM, the (n+L̃)th-tier truncation with L̃=2N(sigma)N(nu) yields the exact density 
      operators up to the nth tier. Here, N(sigma) = 2 for fermionic systems and N(nu) is 
      the system degrees of freedom. For noninteracting systems, L̃ is further reduced 
      by half. Such an exact termination pattern originates from the Pauli exclusion 
      principle for fermions, and it holds true regardless of the system-environment 
      coupling strength, the number of coupling reservoirs, or the specific scheme 
      employed to unravel the environment memory contents. The relatively small L̃ 
      emphasizes the nonperturbative nature of the HEOM theory. We also propose a 
      simplified HEOM approach to further reduce the memory cost for practical 
      calculations.
FAU - Han, Lu
AU  - Han L
AD  - Hefei National Laboratory for Physical Sciences at the Microscale and Synergetic 
      Innovation Center of Quantum Information and Quantum Physics, University of 
      Science and Technology of China, Hefei, Anhui 230026, China.
FAU - Zhang, Hou-Dao
AU  - Zhang HD
AUID- ORCID: 0000000217291583
AD  - Hefei National Laboratory for Physical Sciences at the Microscale and Synergetic 
      Innovation Center of Quantum Information and Quantum Physics, University of 
      Science and Technology of China, Hefei, Anhui 230026, China.
FAU - Zheng, Xiao
AU  - Zheng X
AUID- ORCID: 0000000298041833
AD  - Hefei National Laboratory for Physical Sciences at the Microscale and Synergetic 
      Innovation Center of Quantum Information and Quantum Physics, University of 
      Science and Technology of China, Hefei, Anhui 230026, China.
FAU - Yan, YiJing
AU  - Yan Y
AD  - Hefei National Laboratory for Physical Sciences at the Microscale and iChEM, 
      University of Science and Technology of China, Hefei, Anhui 230026, China.
LA  - eng
PT  - Journal Article
PL  - United States
TA  - J Chem Phys
JT  - The Journal of chemical physics
JID - 0375360
EDAT- 2018/06/25 06:00
MHDA- 2018/06/25 06:01
CRDT- 2018/06/25 06:00
PHST- 2018/06/25 06:00 [entrez]
PHST- 2018/06/25 06:00 [pubmed]
PHST- 2018/06/25 06:01 [medline]
AID - 10.1063/1.5034776 [doi]
PST - ppublish
SO  - J Chem Phys. 2018 Jun 21;148(23):234108. doi: 10.1063/1.5034776.