Device-independent tomography of physical systems

Friday, April 6, 2018

11.30 a.m.

ISI seminar room 2nd floor

Michele Dall' Arno Centre for Quantum Technologies, National University of Singapore

Tomography is the process of reconstructing a mathematical model of a given system, by inputing a probe which is measured at the output. Usual tomographic reconstruction is based not only on observed correlations between such inputs and outputs, but also on assumptions about the way in which such correlations have been obtained, that is, about the probe and measurement. Here, we abandon any such assumptions -- that is, we adopt a device-independent approach -- and derive tomographic reconstruction solely based on observed input/output correlations. To this aim, we introduce a minimality criterion, inspired by Jaynes' maxent principle: among all models that explain the observed correlations, we prefer the minimal explanation, that is, the one compatible with the minimum volume of correlations. Ongoing experimental implementations have already shown the feasibility of our protocol for the tomographic reconstruction of quantum systems. So far, any disagreement with usual tomography has pinpointed the incorrect calibration of the probe or measurement over which usual tomography depends upon.

Michele Dall' Arno is a mathematical physicists with a special interest in information theory. After his PhD in Pavia, with Prof. Mauro D’Ariano, he worked in ICFO (Barcelona), Nagoya University (Japan), and the Centre for Quantum Technologies (Singapore), collaborating with Prof. Antonio Acin, Francesco Buscemi, and Vlatko Vedral, respectively. His main research interests are the theory of correlations and the device-independent approach, with applications (including experimental ones) to the theory of communication and to state tomography.