Time-Dependent Approaches to Open Quantum Systems

Masaaki Tokieda, Kouichi Hagino

Research output: Contribution to journalArticlepeer-review

Abstract

Couplings of a system to other degrees of freedom (that is, environmental degrees of freedom) lead to energy dissipation when the number of environmental degrees of freedom is large enough. Here, we discuss quantal treatments for such energy dissipation. To this end, we discuss two different time-dependent methods. One is to introduce an effective time-dependent Hamiltonian, which leads to a classical equation of motion as a relationship among expectation values of quantum operators. We apply this method to a heavy-ion fusion reaction and discuss the role of dissipation on the penetrability of the Coulomb barrier. The other method is to start with a Hamiltonian with environmental degrees of freedom and derive an equation that the system degree of freedom obeys. For this, we present a new efficient method to solve coupled-channels equations that can be easily applied even when the dimension of the coupled-channels equations is huge.

Original languageEnglish
Article number8
JournalFrontiers in Physics
Volume8
DOIs
Publication statusPublished - 2020 Feb 7

Keywords

  • Caldeira-Leggett model
  • barrier transmission
  • fusion reactions
  • open quantum systems
  • quantum friction

ASJC Scopus subject areas

  • Biophysics
  • Materials Science (miscellaneous)
  • Mathematical Physics
  • Physics and Astronomy(all)
  • Physical and Theoretical Chemistry

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