4 papers
Asymptotically optimal purification of noisy unitary channels in any dimension
Ryotaro Niwa, Satoshi Yoshida, Mio Murao
We consider the problem of noisy unitary purification. Given access to an unknown -dimensional unitary channel followed by depolarizing noise of strength , we aim to construc…
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…
Singular value transformation for unknown quantum channels
Ryotaro Niwa, Zane Marius Rossi, Philip Taranto +1
Given the ability to apply an unknown quantum channel acting on a -dimensional system, we develop a quantum algorithm for transforming its singular values. The spectrum of a qua…