Massimo Frigerio - Academia.edu (original) (raw)
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Papers by Massimo Frigerio
arXiv: Quantum Physics, 2020
Nonclassicality according to the singularity or negativity of the Glauber P-function is a powerfu... more Nonclassicality according to the singularity or negativity of the Glauber P-function is a powerful resource in quantum information, with relevant implications in quantum optics. In a Gaussian setting, and for a system of two modes, we explore how P-nonclassicality may be conditionally generated or influenced on one mode by Gaussian measurements on the other mode. Starting from the class of two-mode squeezed thermal states (TMST), we introduce the notion of nonclassical steering (NS) and the graphical tool of Gaussian triangoloids. In particular, we derive a necessary and sufficient condition for a TMST to be nonclassically steerable, and show that entanglement is only necessary. We also apply our criterion to noisy propagation of a twin-beam state, and evaluate the time after which NS is no longer achievable. We then generalize the notion of NS to the full set of Gaussian states of two modes, and recognize that it may occur in a weak form, which does not imply entanglement, and in a...
arXiv: Quantum Physics, 2020
Singularity or negativity of Glauber P-function is a widespread notion of nonclassicality, with i... more Singularity or negativity of Glauber P-function is a widespread notion of nonclassicality, with important implications in quantum optics and with the character of an irreducible resource. Here we explore how P-nonclassicality may be generated by conditional Gaussian measurements on bipartite Gaussian states. This nonclassical steering may occur in a weak form, which does not imply entanglement, and in a strong form that implies EPR-steerability and thus entanglement. We show that field quadratures are the best measurements to remotely generate nonclassicality, and exploit this result to derive necessary and sufficient conditions for weak and strong nonclassical steering. For two-mode squeezed thermal states (TMST), weak and strong nonclassical steering coincide, and merge with the notion of EPR steering. This also provides a new operational interpretation for P-function nonclassicality as the distinctive feature that allows one-party entanglement verification on TMSTs.
Physical Review A, 2021
We put forward a measure based on Gaussian steering to quantify the non-Markovianity of continuou... more We put forward a measure based on Gaussian steering to quantify the non-Markovianity of continuous-variable (CV) Gaussian quantum channels. We employ the proposed measure to assess and compare the non-Markovianity of a quantum Brownian motion (QBM) channel, originating from the interaction with Ohmic and sub-Ohmic environments with spectral densities described by a Lorentz-Drude cutoff, both at high and low temperatures, showing that sub-Ohmic, high temperature environments lead to highly non-Markovian evolution, with cyclic backflows of Gaussian steerability from the environment to the system. Our results add to the understanding of the interplay between quantum correlations and non-Markovianity for CV systems, and could be implemented at the experimental level to quantify non-Markovianity in some physical scenarios.
Physical Review A, 2021
Nonclassicality according to the singularity or negativity of the Glauber P-function is a powerfu... more Nonclassicality according to the singularity or negativity of the Glauber P-function is a powerful resource in quantum information, with relevant implications in quantum optics. In a Gaussian setting, and for a system of two modes, we explore how P-nonclassicality may be conditionally generated or influenced on one mode by Gaussian measurements on the other mode. Starting from the class of two-mode squeezed thermal states (TMST), we introduce the notion of nonclassical steering (NS) and the graphical tool of Gaussian triangoloids. In particular, we derive a necessary and sufficient condition for a TMST to be nonclassically steerable, and show that entanglement is only necessary. We also apply our criterion to noisy propagation of a twin-beam state, and evaluate the time after which NS is no longer achievable. We then generalize the notion of NS to the full set of Gaussian states of two modes, and recognize that it may occur in a weak form, which does not imply entanglement, and in a strong form that implies EPR-steerability and, a fortiori, also entanglement. These two types of NS coincide exactly for TMSTs, and they merge with the previously known notion of EPR steering. By the same token, we recognize a new operational interpretation of P-nonclassicality: it is the distinctive property that allows one-party entanglement verification on TMSTs.
Chemistry - A European Journal, 2017
Synthetic tubulysins 24a-m, having non-hydrolysable N-substituents on tubuvaline (Tuv), were obta... more Synthetic tubulysins 24a-m, having non-hydrolysable N-substituents on tubuvaline (Tuv), were obtained in high purity and good overall yields using a multi-step synthesis. Key step was the formation of differently N-substituted Ile-Tuv fragments 10 via aza-Michael reaction of azido-Ile derivatives 8 with the α,β-unsaturated oxo-thiazole 5. A SAR study using a panel of human tumor cell lines showed strong anti-proliferative activity for all compounds 24a-m, with IC50 values in the sub-nanomolar range, which were distinctly lower than those of Tubulysin A, vinorelbine, and paclitaxel. Furthermore, 24a-m were able to overcome cross-resistance to paclitaxel and vinorelbine in two tumor cell lines with acquired resistance to doxorubicin. Compounds 24e and 24g were selected as leads to evaluate their mechanism of action. In vitro assays showed that both 24e and 24g interfere with tubulin polymerization in a vinca alkaloid-like manner and prevent paclitaxel-induced assembly of tubulin polymers. Both compounds exerted antimitotic activity and induced apoptosis in cancer cells at very low concentrations. Compound 24e also exhibited potent antitumor activity at well tolerated doses on in vivo models of diffuse malignant peritoneal mesothelioma, such as MESOII peritoneal mesothelioma xenografts, whose growth was not significantly affected by vinorelbine. These results indicate that synthetic tubulysins 24 could be used as standalone chemotherapeutic agents in difficult-to-treat cancers.
Journal of the Chemical Society, Perkin Transactions 1, 1988
... Rosanna Bernardi, Pierfrancesco Bravo, Rosanna Cardillo, Dario Ghiringhelli," and Giusep... more ... Rosanna Bernardi, Pierfrancesco Bravo, Rosanna Cardillo, Dario Ghiringhelli," and Giuseppe Resnati CNR-Centro di Studio per le Sostanze Organiche Natural ... fluoro-3-(p-tolylsulphonyl) propan-2-one (3) and of the corresponding sulphenyl derivative (5) with Baker's yeast and ...
Tetrahedron Letters, 2000
... This trouble was solved by using the exact conditions reported by Bartlett for the synthesis ... more ... This trouble was solved by using the exact conditions reported by Bartlett for the synthesis of a phosphorus-containing analogue of Pepstatin (iso-BuCO 2 Cl/NMM in AcOEt)[16] which provided the stereochemically pure pentapeptide 15, which was hydrolyzed with LiOH in ...
Tetrahedron, 1994
ABSTRACT
Tetrahedron: Asymmetry, 2004
The reaction of an enantiomerically pure sulfinimine of trifluoropyruvate with several metal enol... more The reaction of an enantiomerically pure sulfinimine of trifluoropyruvate with several metal enolates is described. The use of TiCl(O-iPr) 3 /LDA produced the corresponding sulfinamides with high stereocontrol. The latter could be smoothly transformed into each enantiomer of a-trifluoromethyl aspartic acid with high ee, which has been previously synthesized only in racemic form.
arXiv: Quantum Physics, 2020
Nonclassicality according to the singularity or negativity of the Glauber P-function is a powerfu... more Nonclassicality according to the singularity or negativity of the Glauber P-function is a powerful resource in quantum information, with relevant implications in quantum optics. In a Gaussian setting, and for a system of two modes, we explore how P-nonclassicality may be conditionally generated or influenced on one mode by Gaussian measurements on the other mode. Starting from the class of two-mode squeezed thermal states (TMST), we introduce the notion of nonclassical steering (NS) and the graphical tool of Gaussian triangoloids. In particular, we derive a necessary and sufficient condition for a TMST to be nonclassically steerable, and show that entanglement is only necessary. We also apply our criterion to noisy propagation of a twin-beam state, and evaluate the time after which NS is no longer achievable. We then generalize the notion of NS to the full set of Gaussian states of two modes, and recognize that it may occur in a weak form, which does not imply entanglement, and in a...
arXiv: Quantum Physics, 2020
Singularity or negativity of Glauber P-function is a widespread notion of nonclassicality, with i... more Singularity or negativity of Glauber P-function is a widespread notion of nonclassicality, with important implications in quantum optics and with the character of an irreducible resource. Here we explore how P-nonclassicality may be generated by conditional Gaussian measurements on bipartite Gaussian states. This nonclassical steering may occur in a weak form, which does not imply entanglement, and in a strong form that implies EPR-steerability and thus entanglement. We show that field quadratures are the best measurements to remotely generate nonclassicality, and exploit this result to derive necessary and sufficient conditions for weak and strong nonclassical steering. For two-mode squeezed thermal states (TMST), weak and strong nonclassical steering coincide, and merge with the notion of EPR steering. This also provides a new operational interpretation for P-function nonclassicality as the distinctive feature that allows one-party entanglement verification on TMSTs.
Physical Review A, 2021
We put forward a measure based on Gaussian steering to quantify the non-Markovianity of continuou... more We put forward a measure based on Gaussian steering to quantify the non-Markovianity of continuous-variable (CV) Gaussian quantum channels. We employ the proposed measure to assess and compare the non-Markovianity of a quantum Brownian motion (QBM) channel, originating from the interaction with Ohmic and sub-Ohmic environments with spectral densities described by a Lorentz-Drude cutoff, both at high and low temperatures, showing that sub-Ohmic, high temperature environments lead to highly non-Markovian evolution, with cyclic backflows of Gaussian steerability from the environment to the system. Our results add to the understanding of the interplay between quantum correlations and non-Markovianity for CV systems, and could be implemented at the experimental level to quantify non-Markovianity in some physical scenarios.
Physical Review A, 2021
Nonclassicality according to the singularity or negativity of the Glauber P-function is a powerfu... more Nonclassicality according to the singularity or negativity of the Glauber P-function is a powerful resource in quantum information, with relevant implications in quantum optics. In a Gaussian setting, and for a system of two modes, we explore how P-nonclassicality may be conditionally generated or influenced on one mode by Gaussian measurements on the other mode. Starting from the class of two-mode squeezed thermal states (TMST), we introduce the notion of nonclassical steering (NS) and the graphical tool of Gaussian triangoloids. In particular, we derive a necessary and sufficient condition for a TMST to be nonclassically steerable, and show that entanglement is only necessary. We also apply our criterion to noisy propagation of a twin-beam state, and evaluate the time after which NS is no longer achievable. We then generalize the notion of NS to the full set of Gaussian states of two modes, and recognize that it may occur in a weak form, which does not imply entanglement, and in a strong form that implies EPR-steerability and, a fortiori, also entanglement. These two types of NS coincide exactly for TMSTs, and they merge with the previously known notion of EPR steering. By the same token, we recognize a new operational interpretation of P-nonclassicality: it is the distinctive property that allows one-party entanglement verification on TMSTs.
Chemistry - A European Journal, 2017
Synthetic tubulysins 24a-m, having non-hydrolysable N-substituents on tubuvaline (Tuv), were obta... more Synthetic tubulysins 24a-m, having non-hydrolysable N-substituents on tubuvaline (Tuv), were obtained in high purity and good overall yields using a multi-step synthesis. Key step was the formation of differently N-substituted Ile-Tuv fragments 10 via aza-Michael reaction of azido-Ile derivatives 8 with the α,β-unsaturated oxo-thiazole 5. A SAR study using a panel of human tumor cell lines showed strong anti-proliferative activity for all compounds 24a-m, with IC50 values in the sub-nanomolar range, which were distinctly lower than those of Tubulysin A, vinorelbine, and paclitaxel. Furthermore, 24a-m were able to overcome cross-resistance to paclitaxel and vinorelbine in two tumor cell lines with acquired resistance to doxorubicin. Compounds 24e and 24g were selected as leads to evaluate their mechanism of action. In vitro assays showed that both 24e and 24g interfere with tubulin polymerization in a vinca alkaloid-like manner and prevent paclitaxel-induced assembly of tubulin polymers. Both compounds exerted antimitotic activity and induced apoptosis in cancer cells at very low concentrations. Compound 24e also exhibited potent antitumor activity at well tolerated doses on in vivo models of diffuse malignant peritoneal mesothelioma, such as MESOII peritoneal mesothelioma xenografts, whose growth was not significantly affected by vinorelbine. These results indicate that synthetic tubulysins 24 could be used as standalone chemotherapeutic agents in difficult-to-treat cancers.
Journal of the Chemical Society, Perkin Transactions 1, 1988
... Rosanna Bernardi, Pierfrancesco Bravo, Rosanna Cardillo, Dario Ghiringhelli," and Giusep... more ... Rosanna Bernardi, Pierfrancesco Bravo, Rosanna Cardillo, Dario Ghiringhelli," and Giuseppe Resnati CNR-Centro di Studio per le Sostanze Organiche Natural ... fluoro-3-(p-tolylsulphonyl) propan-2-one (3) and of the corresponding sulphenyl derivative (5) with Baker's yeast and ...
Tetrahedron Letters, 2000
... This trouble was solved by using the exact conditions reported by Bartlett for the synthesis ... more ... This trouble was solved by using the exact conditions reported by Bartlett for the synthesis of a phosphorus-containing analogue of Pepstatin (iso-BuCO 2 Cl/NMM in AcOEt)[16] which provided the stereochemically pure pentapeptide 15, which was hydrolyzed with LiOH in ...
Tetrahedron, 1994
ABSTRACT
Tetrahedron: Asymmetry, 2004
The reaction of an enantiomerically pure sulfinimine of trifluoropyruvate with several metal enol... more The reaction of an enantiomerically pure sulfinimine of trifluoropyruvate with several metal enolates is described. The use of TiCl(O-iPr) 3 /LDA produced the corresponding sulfinamides with high stereocontrol. The latter could be smoothly transformed into each enantiomer of a-trifluoromethyl aspartic acid with high ee, which has been previously synthesized only in racemic form.