201 citations · 721 across the 42 of their papers we have counts for
33 papers · 1 filter
Multicast quantum network coding as optimal symmetric universal cloning over a quantum network
Go Kato, Mio Murao, Masaki Owari
We study the problem of perfectly multicasting symmetric universal clones of unknown quantum states over quantum networks with free classical communication. We construct a protocol…
Lie-Algebraic Bounds on Quantum Control Time via the Baker-Campbell-Hausdorff Formula
Go Kato, Masaki Owari, Koji Maruyama
The time required to implement a desired unitary operation is a central issue in quantum control, especially for many-body systems with limited control access. While controllabilit…
On the hardness of conversion from entangled proof into separable one
Seiseki Akibue, Go Kato, Seiichiro Tani
A quantum channel whose image approximates the set of separable states is called a disentangler, which plays a prominent role in the investigation of variants of the computational…
Security framework for quantum key distribution with imperfect sources
Guillermo Currás-Lorenzo, Margarida Pereira, Go Kato +2
Imperfect bit-and-basis encoders compromise the security of quantum key distribution (QKD) systems via modulation flaws, side channels and inter-pulse correlations, which invalidat…
Probabilistic state synthesis based on optimal convex approximation
Seiseki Akibue, Go Kato, Seiichiro Tani
When preparing a pure state with a quantum circuit, there is an unavoidable approximation error due to the compilation error in fault-tolerant implementation. A recently proposed a…
Probabilistic unitary synthesis with optimal accuracy
Seiseki Akibue, Go Kato, Seiichiro Tani
The purpose of unitary synthesis is to find a gate sequence that optimally approximates a target unitary transformation. A new synthesis approach, called probabilistic synthesis, h…
Verifiable homodyne measurement for detecting non-local properies of light
Go Kato, Kiyoshi Tamaki, Masaki Owari +1
The homodyne detection is one of the most basic tools for identifying the quantum state of light. It has been used to detect useful non-local properties, such as entanglement for t…
Modified BB84 quantum key distribution protocol robust to source imperfections
Margarida Pereira, Guillermo Currás-Lorenzo, Álvaro Navarrete +4
The Bennett-Brassard 1984 (BB84) protocol is the most widely implemented quantum key distribution (QKD) scheme. However, despite enormous theoretical and experimental efforts in th…
Quadratic improvement on accuracy of approximating pure quantum states and unitary gates by probabilistic implementation
Seiseki Akibue, Go Kato, Seiichiro Tani
Pure quantum states are often approximately encoded as classical bit strings such as those representing probability amplitudes and those describing circuits that generate the quant…
Security of round-robin differential-phase-shift quantum key distribution protocol with correlated light sources
Akihiro Mizutani, Go Kato
Among various quantum key distribution (QKD) protocols, the round-robin differential-phase-shift (RRDPS) protocol has a unique feature that its security is guaranteed without monit…
Bounds for nonadiabatic transitions
Takuya Hatomura, Go Kato
We discuss bounds for nonadiabatic transitions from the viewpoints of the adiabatic perturbation theory and the quantum speed limit. We show that the amount of nonadiabatic transit…
Single-Shot Secure Quantum Network Coding for General Multiple Unicast Network with Free One-Way Public Communication
Go Kato, Masaki Owari, Masahito Hayashi
It is natural in a quantum network system that multiple users intend to send their quantum message to their respective receivers, which is called a multiple unicast quantum network…
Tight finite-key security for twin-field quantum key distribution
Guillermo Currás-Lorenzo, Alvaro Navarrete, Koji Azuma +3
Quantum key distribution (QKD) offers a reliable solution to communication problems that require long-term data security. For its widespread use, however, the rate and reach of QKD…
Quantum key distribution with correlated sources
Margarida Pereira, Go Kato, Akihiro Mizutani +2
In theory, quantum key distribution (QKD) offers information-theoretic security. In practice, however, it does not due to the discrepancies between the assumptions used in the secu…
Perfect discrimination of non-orthogonal quantum states with posterior classical partial information
Seiseki Akibue, Go Kato, Naoki Marumo
The indistinguishability of non-orthogonal pure states lies at the heart of quantum information processing. Although the indistinguishability reflects the impossibility of measurin…
Linear programs for entanglement and key distribution in the quantum internet
Stefan Bäuml, Koji Azuma, Go Kato +1
Quantum networks will allow to implement communication tasks beyond the reach of their classical counterparts. A pressing and necessary issue for the design of quantum network prot…
Quantum key distribution with setting-choice-independently correlated light sources
Akihiro Mizutani, Go Kato, Koji Azuma +6
Despite the enormous theoretical and experimental progress made so far in quantum key distribution (QKD), the security of most existing QKD implementations is not rigorously establ…
Algebra and Hilbert space structures induced by quantum probes
Go Kato, Masaki Owari, Koji Maruyama
In the general setting of quantum controls, it is unrealistic to control all of the degrees of freedom of a quantum system. We consider a scenario where our direct access is restri…
Bipartite discrimination of independently prepared quantum states as a counterexample to a parallel repetition conjecture
Seiseki Akibue, Go Kato
For distinguishing quantum states sampled from a fixed ensemble, the gap in bipartite and single-party distinguishability can be interpreted as a nonlocality of the ensemble. In th…
Versatile relative entropy bounds for quantum networks
Luca Rigovacca, Go Kato, Stefan Bäuml +3
We provide a versatile upper bound on the number of maximally entangled qubits, or private bits, shared by two parties via a generic adaptive communication protocol over a quantum…
Secure Quantum Network Coding on Butterfly Network
Masaki Owari, Go Kato, Masahito Hayashi
Quantum network coding on the butterfly network has been studied as a typical example of quantum multiple cast network. We propose secure quantum network coding on the butterfly ne…
Information-theoretic security proof of differential-phase-shift quantum key distribution protocol based on complementarity
Akihiro Mizutani, Toshihiko Sasaki, Go Kato +2
We show the information-theoretic security proof of the differential-phase-shift (DPS) quantum key distribution (QKD) protocol based on the complementarity approach [arXiv:0704.366…
Differential-phase-shift quantum key distribution protocol with small number of random delays
Yuki Hatakeyama, Akihiro Mizutani, Go Kato +2
The differential-phase-shift (DPS) quantum key distribution (QKD) protocol was proposed aiming at simple implementation, but it can tolerate only a small disturbance in a quantum c…
Security of quantum key distribution with iterative sifting
Kiyoshi Tamaki, Hoi-Kwong Lo, Akihiro Mizutani +4
Several quantum key distribution (QKD) protocols employ iterative sifting. After each quantum transmission round, Alice and Bob disclose part of their setting information (includin…