Macroscopic Quantum Superpositions via Dynamics in a Wide Double-Well Potential

TL;DR

This paper proposes a method to rapidly create macroscopic quantum superpositions of a levitated particle's center of mass using a double-well potential, enabling exploration of quantum effects at large scales.

Contribution

It introduces a scalable, general approach for generating macroscopic quantum states in various systems by evolving particles in a double-well potential after cooling.

Findings

Analysis of noise and decoherence effects relevant to experiments

Proposal to use two particles to reduce collective noise impacts

Potential to generate quantum states at unprecedented length and mass scales

Abstract

We present an experimental proposal for the rapid preparation of the center of mass of a levitated particle in a macroscopic quantum state, that is a state delocalized over a length scale much larger than its zero-point motion and that has no classical analog. This state is prepared by letting the particle evolve in a static double-well potential after a sudden switchoff of the harmonic trap, following initial center-of-mass cooling to a sufficiently pure quantum state. We provide a thorough analysis of the noise and decoherence that is relevant to current experiments with levitated nano- and microparticles. In this context, we highlight the possibility of using two particles, one evolving in each potential well, to mitigate the impact of collective sources of noise and decoherence. The generality and scalability of our proposal make it suitable for implementation with a wide range of systems, including single atoms, ions, and Bose-Einstein condensates. Our results have the potential to enable the generation of macroscopic quantum states at unprecedented scales of length and mass, thereby paving the way for experimental exploration of the gravitational field generated by a source mass in a delocalized quantum state.