A breaking molecule can erase its own quantum history and make patterns vanish and then reappear.
April 20, 2026
Original Paper
Entanglement and photoelectron holography in dissociative photoionization: molecular quantum eraser
arXiv · 2604.16107
The Takeaway
The quantum eraser experiment is a famous demonstration where observing a particle's path destroys its wave behavior. This research observed this exact phenomenon occurring inside a single molecule as it was blasted by light. An electron interference pattern disappears because it becomes entangled with the remaining piece of the molecule. By selecting only a specific state of that leftover ion, the interference pattern suddenly flickers back into existence. This shows that the fundamental rules of quantum information apply to complex chemical reactions, not just isolated particles. It gives scientists a way to manipulate the quantum memory of molecules during a reaction.
From the abstract
In a double-slit experiment with a bipartite system, the visibility of interference fringes depends on the availability of which-way information. Here, we report the formation of a Bell-like state of photoelectron and residual ion in the multiphoton dissociative ionization of the D$_2$ molecule. Evidence for entanglement is provided by the correlated emission directions of photoelectron and ion, which is observed using a COLTRIMS reaction microscope. In the presence of this correlation, the holo