9 papers
Optimal tomography of bosonic and fermionic Gaussian states
Senrui Chen, Marco Fanizza, Filippo Girardi +4
The sample complexity is the minimum number of copies required to learn an accurate classical description of a quantum state. Bosonic and fermionic Gaussian quantum states are fami…
Tumula information and doubly minimized Petz Renyi lautum information
Lukas Schmitt, Filippo Girardi, Laura Burri
We study a doubly minimized variant of the lautum information - a reversed analogue of the mutual information - defined as the minimum relative entropy between any product state an…
Improved Lower Bounds for Learning Quantum Channels in Diamond Distance
Aadil Oufkir, Filippo Girardi
We prove that learning an unknown quantum channel with input dimension , output dimension , and Choi rank to diamond distance requires $ Ω\!\left( \frac…
Zero-Error List Decoding for Classical-Quantum Channels
Marco Dalai, Filippo Girardi, Ludovico Lami
The aim of this work is to study the zero-error capacity of pure-state classical-quantum channels in the setting of list decoding. We provide an achievability bound for list-size t…
Random purification channel for passive Gaussian bosons
Francesco Anna Mele, Filippo Girardi, Senrui Chen +2
The random purification channel, which, given copies of an unknown mixed state , prepares copies of an associated random purification, has proved to be an extremely valu…
Random Stinespring superchannel: converting channel queries into dilation isometry queries
Filippo Girardi, Francesco Anna Mele, Haimeng Zhao +2
The recently introduced random purification channel, which converts copies of an arbitrary mixed quantum state into copies of the same uniformly random purification, has em…
Random purification channel made simple
Filippo Girardi, Francesco Anna Mele, Ludovico Lami
The recently introduced random purification channel, which converts i.i.d. copies of any mixed quantum state into a uniform convex combination of i.i.d. copies of its purif…
Is it Gaussian? Testing bosonic quantum states
Filippo Girardi, Freek Witteveen, Francesco Anna Mele +4
Gaussian states are widely regarded as one of the most relevant classes of continuous-variable (CV) quantum states, as they naturally arise in physical systems and play a key role…
Umlaut information
Filippo Girardi, Aadil Oufkir, Bartosz Regula +3
The sphere-packing bound quantifies the error exponent for noisy channel coding for rates above a critical value. Here, we study the zero-rate limit of the sphere-packing bound and…