83 citations · 226 across the 13 of their papers we have counts for
13 papers
Absorption to Fluctuating Bunching States in Non-Unitary Boson Dynamics
Ken Mochizuki, Ryusuke Hamazaki
We show that noisy nonunitary dynamics of bosons drives arbitrary initial states into a novel fluctuating bunching state, where all bosons occupy one time-dependent mode. We propos…
Distinguishability Transitions in Non-Unitary Boson Sampling Dynamics
Ken Mochizuki, Ryusuke Hamazaki
We discover novel transitions characterized by distinguishability of bosons in non-unitary dynamics with parity-time () symmetry. We show that symmetry…
Band structures under non-Hermitian periodic potentials: Connecting nearly-free and bi-orthogonal tight-binding models
Ken Mochizuki, Tomoki Ozawa
We explore band structures of one-dimensional open systems described by periodic non-Hermitian operators, based on continuum models and tight-binding models. We show that imaginary…
Topological phases protected by shifted sublattice symmetry in dissipative quantum systems
Makio Kawasaki, Ken Mochizuki, Hideaki Obuse
Dissipative dynamics of quantum systems can be classified topologically based on the correspondence between the Lindbladian in the Gorini-Kossakowski-Sudarshan-Lindblad equation an…
Extrinsic topology of Floquet anomalous boundary states in quantum walks
Takumi Bessho, Ken Mochizuki, Hideaki Obuse +1
Bulk-boundary correspondence is a fundamental principle for topological phases where bulk topology determines gapless boundary states. On the other hand, it has been known that cor…
Fate of Topological Edge States in Disordered Periodically-driven Nonlinear Systems
Ken Mochizuki, Kaoru Mizuta, Norio Kawakami
We explore topological edge states in periodically driven nonlinear systems. Based on a self-consistency method adjusted to periodically driven systems, we obtain stationary states…
Statistical properties of eigenvalues of the non-Hermitian Su-Schrieffer-Heeger model with random hopping terms
Ken Mochizuki, Naomichi Hatano, Joshua Feinberg +1
We explore the eigenvalue statistics of a non-Hermitian version of the Su-Schrieffer-Heeger model, with imaginary on-site potentials and randomly distributed hopping terms. We find…
Topological Quantum Walk with Discrete Time-Glide Symmetry
Ken Mochizuki, Takumi Bessho, Masatoshi Sato +1
Discrete quantum walks are periodically driven systems with discrete time evolution. In contrast to ordinary Floquet systems, no microscopic Hamiltonian exists, and the one-period…
Stability of topologically protected edge states in nonlinear quantum walks: Additional bifurcations unique to Floquet systems
Ken Mochizuki, Norio Kawakami, Hideaki Obuse
Recently, effects of nonlinearity on topologically nontrivial systems have attracted attention and the stability of topologically protected edge states has been studied for a quant…
Bulk-edge correspondence and stability of multiple edge states of a symmetric non-Hermitian system by using non-unitary quantum walks
Makio Kawasaki, Ken Mochizuki, Norio Kawakami +1
Topological phases and the associated multiple edge states are studied for parity and time-reversal symmetric non-Hermitian open quantum systems by constructing a…
Bulk-edge correspondence in nonunitary Floquet systems with chiral symmetry
Ken Mochizuki, Dakyeong Kim, Norio Kawakami +1
We study topological phases in one-dimensional open Floquet systems driven by chiral symmetric nonunitary time evolution. We derive a procedure to calculate topological numbers fro…
Effects of disorder on non-unitary symmetric quantum walks
Ken Mochizuki, Hideaki Obuse
symmetry, namely, a combined parity and time-reversal symmetry can make non-unitary quantum walks exhibit entirely real eigenenergy. However, it is known that the co…
Explicit definition of symmetry for non-unitary quantum walks with gain and loss
Ken Mochizuki, Dakyeong Kim, Hideaki Obuse
symmetry, that is, a combined parity and time-reversal symmetry is a key milestone for non-Hermite systems exhibiting entirely real eigenenergy. In the present work,…