2025/03/26 by Gregoire F. M. Tomassi, Daniel Veldhuizen, Tomassi, Gregoire F. M. +13 · 1 voice · 7 citations
#quant-ph #physics.atom-ph
paper · pdf · doi:10.48550/arxiv.2503.20707
While the wave packet of a massive particle grows linearly under free dynamics, it grows exponentially in an inverted harmonic potential, offering a pathway to rapidly increase quantum fluctuations to macroscopic dimensions. In this work, we experimentally demonstrate this principle by expanding the center-of-mass thermal state of a 125nm silica nanoparticle to a position uncertainty of 43.4nm within 260 μs. This expansion, achieved using an inverted dark potential to minimize decoherence from photon recoil, represents a 952-fold increase, reaching a scale comparable to the nanoparticle's physical size. This work represents a key advancement toward preparing macroscopic quantum superpositions at unprecedented mass and length scales.