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Résumé |
Many-body quantum systems are the most powerful computers allowed by Nature. In this
talk, I present two bounds to our ability to process information with them,
elucidating their implications.
First Part:
I discuss universal, quantitative bounds on quantum correlations in many-body
systems: they are bounded by the shareable classical information between parts of the
system. As an important consequence, objectivity of measurement results arises only
when quantum correlations between an information source and a network of recipients
are selectively suppressed. That is, consensus among observers responsible for
objective classical reality is an emergent attribute of Quantum Mechanics.
Refs.: arXiv:2202.09328, PRL128, 010401 (2022)
Second part:
I introduce a geometric information measure that rigorously evaluates the difference
between two complex configurations of arbitrarily large quantum systems, e.g.,
thousands of interacting atoms. The result is instrumental in finding the maximum
conversion rate of physical resources, such as energy and time, into quantum
computational power. A simple but universally valid inequality, formally similar to
the Heisenberg uncertainty relations, bounds the size of a program that creates a
target quantum state by its experimental cost.
Ref.: PRL 126, 170502 (2021), PRL122, 010505 (2019), Editors’ Suggestion |
