10 papers
Entanglement Generation Beyond Quantum Theory: From Product States to Popescu-Rohrlich Boxes
Shun Umekawa, Akihiro Hokkyo, Hayato Arai +1
Entanglement generation is a fundamental dynamical capability in quantum information science and underpins many quantum advantages. While quantum theory enables it through unitary…
Generating collective spin cat states via photon-number measurements near the Dicke critical point
Taiga Nakamoto, Shohei Imai, Kazuaki Takasan
We propose a method for generating collective spin cat states in a cavity-coupled atomic ensemble by exploiting strong light-matter entanglement and anti-squeezing associated with…
One-dimensional extended Hubbard model coupled with an optical cavity
Taiga Nakamoto, Kazuaki Takasan, Naoto Tsuji
We study the one-dimensional extended Hubbard model coupled with an optical cavity, which describes an interplay of the effect of vacuum fluctuation of light and the quantum phase…
Ferromagnetism in tilted fermionic Mott insulators
Kazuaki Takasan, Masaki Tezuka
We investigate the magnetism in tilted fermionic Mott insulators. With a small tilt, the fermions are still localized and form a Mott-insulating state, where the localized spins in…
Dielectric breakdown of strongly correlated insulators in one dimension: Universal formula from non-Hermitian sine-Gordon theory
Kazuaki Takasan, Masaya Nakagawa, Norio Kawakami
Application of a strong electric field to insulators induces a finite current. This phenomenon is called dielectric breakdown and is known as a fundamental nonequilibrium and nonli…
Current-Enabled Optical Conductivity of Collective Modes in Unconventional Superconductors
Gerrit Niederhoff, Ryusei Kataoka, Kazuaki Takasan +1
We theoretically investigate the current-enabled linear optical conductivity of collective modes in superconductors with unconventional pairing symmetries. After deriving general f…