225 citations · 315 across the 9 of their papers we have counts for
9 papers
Secret key rate of a continuous-variable quantum-key-distribution scheme when the detection process is inaccessible to eavesdroppers
Ryo Namiki, Akira Kitagawa, Takuya Hirano
We have developed a method to calculate a secret key rate of a continuous-variable quantum-key-distribution scheme using four coherent states and postselection for a general model…
Quantum description of electromagnetic fields in waveguides
Akira Kitagawa
Using quantum theory, we study the propagation of an optical field in an inhomogeneous dielectric, and apply this scheme to traveling optical fields in a waveguide. We introduce a…
Unambiguous discrimination among oracle operators
Anthony Chefles, Akira Kitagawa, Masahiro Takeoka +2
We address the problem of unambiguous discrimination among oracle operators. The general theory of unambiguous discrimination among unitary operators is extended with this applicat…
Entanglement quantification with Fisher information
Akira kitagawa, Masahiro Takeoka, Masahide Sasaki +1
We show that the Fisher information associated with entanglement-assisted coding has a monotonic relationship with the logarithmic negativity, an important entanglement measure, fo…
Entanglement evaluation of non-Gaussian states generated by photon subtraction from squeezed states
Akira Kitagawa, Masahiro Takeoka, Masahide Sasaki +1
We consider the problem of evaluating the entanglement of non-Gaussian mixed states generated by photon subtraction from entangled squeezed states. The entanglement measures we use…
Effective squeezing enhancement via measurement-induced non-Gaussian operation and its application to dense coding scheme
Akira Kitagawa, Masahiro Takeoka, Kentaro Wakui +1
We study the measurement-induced non-Gaussian operation on the single- and two-mode \textit{Gaussian} squeezed vacuum states with beam splitters and on-off type photon detectors, w…