22 citations · 115 across the 11 of their papers we have counts for
11 papers
A unified view of direct measurement of quantum states, processes, and measurements
Kazuhisa Ogawa, Takumi Matsuura, Akihisa Tomita
The dynamics of a quantum system are characterized by three components: quantum state, quantum process, and quantum measurement. The proper measurement of these components is a cru…
Complex counterpart of variance in quantum measurements for pre- and post-selected systems
Kazuhisa Ogawa, Natsuki Abe, Hirokazu Kobayashi +1
The variance of an observable in a pre-selected quantum system, which is always real and non-negative, appears as an increase in the probe wave packet width in indirect measurement…
Direct measurement of ultrafast temporal wavefunctions
Kazuhisa Ogawa, Takumi Okazaki, Hirokazu Kobayashi +2
The large capacity and robustness of information encoding in the temporal mode of photons is important in quantum information processing, in which characterizing temporal quantum s…
Operational formulation of weak values without probe systems
Kazuhisa Ogawa, Hirokazu Kobayashi, Akihisa Tomita
Weak values are the fundamental values for observables in a pre- and post-selected system. Weak values are typically measured by weak measurement, in which weak values appear in th…
A framework for measuring weak values without weak interactions and its diagrammatic representation
Kazuhisa Ogawa, Osamu Yasuhiko, Hirokazu Kobayashi +2
Weak values are typically obtained experimentally by performing weak measurements, which involve weak interactions between the measured system and a probe. However, the determinati…
Classical reconstruction of interference patterns of position-wavevector-entangled photon pairs by time-reversal method
Kazuhisa Ogawa, Hirokazu Kobayashi, Akihisa Tomita
The quantum interference of entangled photons forms a key phenomenon underlying various quantum-optical technologies. It is known that the quantum interference patterns of entangle…
Classical realization of dispersion-canceled, artifact-free, and background-free optical coherence tomography
Kazuhisa Ogawa, Masao Kitano
Quantum-optical coherence tomography (Q-OCT) provides a dispersion-canceled axial-imaging method, but its practical use is limited by the weakness of the light source and by artifa…
Observation of nonlinear variations in three-vertex geometric phase in two-photon polarization qutrit
Kazuhisa Ogawa, Shuhei Tamate, Hirokazu Kobayashi +2
We experimentally observed nonlinear variations in the three-vertex geometric phase in a two- photon polarization qutrit. The three-vertex geometric phase is defined by three quant…
Classical Realization of Dispersion Cancellation by Time-Reversal Method
Kazuhisa Ogawa, Shuhei Tamate, Toshihiro Nakanishi +2
We propose a classical optical interferometry scheme that reproduces dispersion-insensitive Hong-Ou-Mandel interferograms. The interferometric scheme is derived from a systematic m…
Time-reversed two-photon interferometry for phase super-resolution
Kazuhisa Ogawa, Shuhei Tamate, Hirokazu Kobayashi +2
We observed two-photon phase super-resolution in an unbalanced Michelson interferometer with classical Gaussian laser pulses. Our work is a time-reversed version of a two-photon in…
Bloch sphere representation of three-vertex geometric phases
Shuhei Tamate, Kazuhisa Ogawa, Masao Kitano
The properties of the geometric phases between three quantum states are investigated in a high-dimensional Hilbert space using the Majorana representation of symmetric quantum stat…