46 citations · 151 across the 7 of their papers we have counts for
4 papers · 1 filter
Deterministic three-photon down-conversion by a passive ultrastrong cavity-QED system
Kazuki Koshino, Tomohiro Shitara, Ziqiao Ao +1
In ultra- and deep-strong cavity quantum electrodynamics (QED) systems, many intriguing phenomena that do not conserve the excitation number are expected to occur. In this study, w…
Nonclassicality of open circuit QED systems in the deep-strong coupling regime
Tomohiro Shitara, Motoaki Bamba, Fumiki Yoshihara +4
We investigate theoretically how the ground state of a qubit-resonator system in the deep-strong coupling (DSC) regime is affected by the coupling to an environment. We employ as a…
Determining the Continuous Family of Quantum Fisher Information from Linear Response Theory
Tomohiro Shitara, Masahito Ueda
The quantum Fisher information represents the continuous family of metrics on the space of quantum states and places the fundamental limit on the accuracy of quantum state estimati…
Tradeoff Relation between Information and Disturbance in Quantum Measurement
Tomohiro Shitara, Yui Kuramochi, Masahito Ueda
When we extract information from a system by performing a quantum measurement, the state of the system is disturbed due to the backaction of the measurement. Numerous studies have…