Modern machine learning applications require huge artificial networks demanding in computational power and memory. Light-based platforms promise ultra-fast and energy-efficient hardware, which may help in realizing next-generation data processing devices. However, current photonic networks are limited by the number of input-output nodes that can be processed in a single shot. This restricted network capacity prevents their application to relevant large-scale problems such as natural language processing. Here, we realize a photonic processor with a capacity exceeding 1.5×1010 optical nodes, more than one order of magnitude larger than any previous implementation, which enables photonic large-scale text encoding and classification. By exploiting the full three-dimensional structure of the optical field propagating in free space, we overcome the interpolation threshold and reach the over-parametrized region of machine learning, a condition that allows high-performance natural language processing with a minimal fraction of training points. Our results provide a novel solution to scale-up light-driven computing and open the route to photonic language processing.
Quantum field theory beyond Minkowski is still largely unexplored, and the links with quantum information are surprising.
We know that the Minkowski vacuum appears as a thermal state in a uniformly accelerated frame (Rindler/Unruh) or in the proximity of a black hole (Hawking).
Beyond Unruh and Hawking radiation, how do quantum states appear to a noninertial observer? We derive a general technique to understand the way acceleration alters Minkowski-Fock states. It turns out that one can use and engineer quantum correlations to measure acceleration. But a lot of work is still needed with advanced mathematical approaches, although these new general results may be useful for many applications.
Minkowski-Fock states in accelerated frames
Riccardo Falcone and Claudio Conti
An explicit Wigner formulation of Minkowski particle states for non-inertial observers is unknown. Here, we derive a general prescription to compute the characteristic function for Minkowski-Fock states in accelerated frames. For the special case of single-particle and two-particle states, this method enables to derive mean values of particle numbers and correlation function in the momentum space, and the way they are affected by the acceleration of the observer. We show an indistinguishability between Minkowski single-particle and two-particle states in terms of Rindler particle distribution that can be regarded as a way for the observer to detect any acceleration of the frame. We find that for two-particle states the observer is also able to detect acceleration by measuring the correlation between Rindler particles with different momenta.