4 papers
Scaling-optimal purification of noisy qubit unitary channels
Ryotaro Niwa, Satoshi Yoshida, Koki Ono +5
We consider the problem of purifying noisy qubit unitary channels. Given the ability to apply an unknown qubit unitary channel followed by depolarizing noise, we aim to construct a…
Random dilation superchannel
Satoshi Yoshida, Ryotaro Niwa, Takeru Utsumi +2
We present a quantum circuit that implements the random dilation superchannel, transforming parallel queries of an unknown quantum channel into the same number of parallel queries…
Explicit decoders using fixed-point amplitude amplification based on QSVT
Takeru Utsumi, Yoshifumi Nakata
Reliably transmitting quantum information via a noisy quantum channel is a central challenge in quantum information science. While constructing a decoder is crucial to this goal, l…
Quantum algorithms for Uhlmann transformation
Takeru Utsumi, Yoshifumi Nakata, Qisheng Wang +1
Uhlmann's theorem is a central result in quantum information theory, which associates the closeness of two quantum states with that of their purifications. The theorem also well ch…