334 citations · 2k across the 81 of their papers we have counts for
81 papers
Quantum Dynamics, Master Equation and Equilibrium for a Qubit Coupled to a Thermal Boson Field
Hiromichi Nakazato, Saverio Pascazio
We analytically derive the exact -- though formal -- master equation for a two-level quantum system (qubit) interacting with a bosonic environment within the rotating-wave approxim…
CP conditions for GKSL-like master equations
Akane Watanabe, Takayuki Suzuki, Makoto Unoki +1
The complete positivity (CP) of a quantum dynamical map (QDM) is, in general, difficult to show when its master equation (ME) does not conform to the Gorini-Kossakowski-Sudarshan-L…
Central Charge in Quantum Optics
Daniel Burgarth, Paolo Facchi, Hiromichi Nakazato +2
The product of two unitaries can normally be expressed as a single exponential through the famous Baker-Campbell-Hausdorff formula. We present here a counterexample in quantum opti…
Spin-spin coupling-based quantum and classical phase transitions in two-impurity spin-boson models
Roberto Grimaudo, Antonino Messina, Hiromichi Nakazato +2
The class of two-interacting-impurity spin-boson models with vanishing transverse fields on the spin-pair is studied. The model can be exactly mapped into two independent standard…
Generalized Adiabatic Impulse Approximation
Takayuki Suzuki, Hiromichi Nakazato
Non-adiabatic transitions in multilevel systems appear in various fields of physics, but it is not easy to analyze their dynamics in general. In this paper, we propose to extend th…
Vacuum decay and fermion total reflection by the Klein step
H. Nakazato, M. Ochiai
The so-called Klein tunneling is re-examined within the framework of quantum field theory, but from a different point of view on the asymptotic states. We treat it as a one-dimensi…