n this talk, I shall present our new technique to detect non-classicality under the assumption that the dynamics is known [1,2,3], based on an early insight by Tsirelson [4]. Most of the talk will focus on one and two harmonic oscillators, although the results can be widely generalized (we have shown them for precessing discrete systems [1], as well as for continuous systems with arbitrary time-independent Hamiltonian dynamics [3]). Among the highlights you can expect are the following:<\/p>\n\n\n\n
a) The criterion is an inequality that no classical model can violate. (This is particularly unusual for entanglement of continuous variable systems [2], where most of the witnesses rely on uncertainty relations, which can be violated by imprecise or badly calibrated measurements).<\/p>\n\n\n\n
b) The criterion requires a single measurement per round; and it is a quadrature measurement, thus routinely feasible. This is a major advantage over tests that require more measurements and constraining assumptions, like Leggett-Garg type tests (which require two sequential measurements and the assumption of non-invasiveness) or tests based on “contextuality” (which require the assumption that several measurements commute).<\/p>\n\n\n\n
c) The states that are detected have a symmetry that makes them suitable for bosonic error correcting codes.<\/p>\n\n\n\n
But most importantly, I shall insist on the main surprise: one can use the very classical dynamics of the harmonic oscillator to detect non-classicality [4].<\/p>\n\n\n\n
[1] L.T. Zaw et al., hys. Rev. A 106, 032222 (2022) https:\/\/arxiv.org\/abs\/2204.10498<\/a><\/p>\n\n\n\n [2] P. Jayachandran et al., Phys. Rev. Lett. 130, 160201 (2023) https:\/\/arxiv.org\/abs\/2210.10357<\/a><\/p>\n\n\n\n [3] L.T. Zaw and V.S., https:\/\/arxiv.org\/abs\/2212.06017<\/a><\/p>\n\n\n\n