Destruction of interference by entanglement

A. M. Rostom

Abstract The gravitationally induced entanglement is a type of quantum entanglement that can be generated between two mesoscopic particles using their Newtonian gravitational interaction. It has attracted a great deal of attention as a new platform for studying quantum aspects of gravity. The present paper analyzes the gravitationally induced entanglement as a pure interference effect and shows that the entanglement is induced solely by a sign change associated with the destructive quantum interference. It is also shown that when the entanglement is non‐maximal, the preparation for destructive interference for one of the particles can recover a maximum visibility interference pattern for the other particle. Therefore, the non‐maximally entangled state can be extremely effective for experimental testing since it can help in reducing requirements (on masses of the particles and their interaction duration, separation distances and sources) and preserve the information about entanglement at the same time. As a result, the improvement in the signal‐to‐noise ratio is demonstrated and a parameter that determines minimal requirements for experimental testing is defined.

Shunlong Luo, Zhengmin Zhang

Andreas Buchleitner, Carlos Viviescas, Markus Tiersch

Peyman Azodi, HERSCHEL A. RABITZ

Despite extensive research on long-range interacting quantum systems, the physical mechanism responsible for the emergence of light cones remains unidentified. This work presents a novel perspective on the origins of locality and emergent light cones in quantum systems with long-range interactions. We identify a mechanism in such spin chains where effective entanglement light cones emerge due to destructive interference among quantum effects that entangle spins. Although long-range entangling effects reach beyond the identified light cone, due to destructive interference, entanglement remains exponentially suppressed in that region, ultimately leading to the formation of the light cone. We demonstrate that this interference not only drives but is also necessary for the emergence of light cones. Furthermore, our analysis reveals that reducing the interaction range weakens this interference, surprisingly increasing the speed of entanglement transport, an effect that opens new experimental opportunities for investigation.

Henok Tadesse

We already know the unconventional and inexplicable behavior of light/photons (and other quantum particles such as electrons) in the Which-Way quantum experiment and entanglement phenomena. In this paper we propose another quantum experiment using a Michelson interferometer. We start with an 'elementary' thought experiment. Suppose that a Michelson interferometer is set up so that the two light beams undergo complete constructive interference, with a single bright spot. Then the distance of one of the mirrors is slightly adjusted for a complete destructive interference: the bright spot disappears. The puzzle is: where does the light go? We suspect that, just like nature does not allow us to know which slit a photon has passed through in the double- slit experiment, nature may not allow us to know 'where the light goes' in the case of (complete) destructive interference. Although nature may not allow a direct measurement, we can understand by reasoning 'where the light goes' during complete destructive interference. This paper reveals the mystery. A simple quantum experiment based on the Michelson interferometer is proposed.