Faculty of Physics University of Warsaw > Events > Seminars > Joint Seminar on Quantum Information and Technologies

Joint Seminar on Quantum Information and Technologies

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until 2023/2024 Quantum Information Seminar

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2013-06-06 (Thursday)
Sali Duża Teoretyczna, Hoża 69 at 10:30  Calendar icon
Dardo Goyeneche (UdeC - Concepción, Chile)

An informationally complete set of measurements for pure states

In this work, we demonstrate that any quantum pure state can bereconstructed from, at most, five probability distributions in everyfinite dimension d. These probability distributions are obtained from 5drank-one projective measurements that can be sorted in 5 orthonormalbases. Our method is adaptative only for a null measure set of purestates. Consequently, our fixed set of five orthonormal bases isinformationaly complete in the sense of Flammia-Silberfarb-Caves (2005).We analyze the quality of the reconstruction when errors in theprobability distributions and noise in the pure state preparation areconsidered. We compare our method with the mutually unbiased basesreconstruction. We show that both methods have the same quality ofreconstruction in dimensions four, five, seven and eight when smallerrors are considered. Finally, we reconstruct a quantum state frommeasurements realized in the laboratory.
2013-05-23 (Thursday)
Sali Duża Teoretyczna, Hoża 69 at 10:30  Calendar icon
Jan Kołodyński (IFT UW)

Efficient tools for quantum metrology with decoherence

Quantum metrology under the idealistic assumption of no decoherenceoffers enhancement of measurement precision that grows withoutrestraint with the number of particles involved. Motivated bypractical applications, we propose tools for quantifying theattainable quantum enhancement based on the geometry of quantumchannels and semi-definite programming that account for the inevitableimpact of the noise. As a result we obtain a simple and direct methodyielding bounds that interpolate between the quantum enhanced scalingcharacteristic for small number of particles and the asymptoticregime, where quantum enhancement amounts to a constant factorimprovement.
2013-05-16 (Thursday)
Sali Duża Teoretyczna, Hoża 69 at 10:30  Calendar icon
Łukasz Rudnicki (Freiburg Institute for Advanced Studies)

Przyjazne kryteria splątania dla zmiennych ciągłych

Entanglement criteria for continuous variables

2013-05-09 (Thursday)
Sali Duża Teoretyczna, Hoża 69 at 10:30  Calendar icon
Mark Tame (Imperial College, London)

Quantum Plasmonics

2013-04-25 (Thursday)
Sali Duża Teoretyczna, Hoża 69 at 10:30  Calendar icon
Sammy Ragy (University of Nottingham)

The role of mutual information in quantum illumination

2013-04-18 (Thursday)
Sali Duża Teoretyczna, Hoża 69 at 10:30  Calendar icon
Bogna Bylicka (UMK, Toruń)

Procesy nie-markowowskie i kwantowa teoria informacji

Quantum information theory and non-Marcovian processes

2013-04-11 (Thursday)
Sali Duża Teoretyczna, Hoża 69 at 10:30  Calendar icon
Daniel McNulty (University of York)

Mutually unbiased bases in composite dimensions

2013-04-04 (Thursday)
Sali Duża Teoretyczna (229), Hoża 69 at 10:30  Calendar icon
Jan Chwedenczuk (IFT UW)

Optimal measurements with a single qubit

2013-03-21 (Thursday)
Sali Duża Teoretyczna (229), Hoża 69 at 10:30  Calendar icon
Radosław Chrapkiewicz (IFD UW)

Korelacje i dekoherencja w wielomodowej pamieci optycznej w parach rubidu

Correlations and decoherence in multimode optical memory in rubidium vapours

2013-03-14 (Thursday)
Sali Duża Teoretyczna (229), Hoża 69 at 10:30  Calendar icon
Vladislav Usenko (Palacky University, Olomouc)

Role of the quantum and classical resources in continuous-variable quantum key distribution