Publications

No second law of entanglement manipulation

Ludovico Lami and Bartosz Regula, Preprint arXiv:2111.02438 (2021)

We prove that the theory of entanglement manipulation is asymptotically irreversible "from first principles", i.e. under all non-entangling operations. This entails that entanglement cannot be quantified in a unique way, i.e. there is no unique entanglement measure that determines all physical transformations, mimicking the role of the entropy in thermodynamics.

To be presented as a short plenary talk at QIP 2022!

Entangleability of cones

Guillaume Aubrun, Ludovico Lami, Carlos Palazuelos, and Martin Plávala, Geom. Funct. Anal. 31(2):181-205, 2021.

See also arXiv:2109.04446 for a clearer exposition of the physical implications.

The first lecture of your standard quantum mechanics course presents the fundamental concept of superposition, demonstrated via the two-slit experiment. The second lecture (optimistically) introduces another fundamental notion, that of entanglement, which we now understand as lying at the heart of the advantages of quantum over classical computing. How are these two notions connected? Well, via the formalism of quantum theory, that is, via the math. But since they are ultimately operational concepts, it is natural to find an operational connection, one that does not rely on the mathematical formalism of quantum theory, and that is thus valid beyond the realm of quantum physics. Here we find such a connection, proving that, within the formalism of general probabilistic theories, two theories are entangleable if and only if they both exhibit local superpositions. To do so, we solve a 45-year old mathematical conjecture about tensor products of cones!

Presented at QIP 2021.