Constructing Nano-Object Quantum Superpositions with a Stern-Gerlach Interferometer

TL;DR

This paper proposes a feasible experimental setup using a Stern-Gerlach interferometer with realistic magnetic field gradients to create large spatial superpositions of massive objects, enabling tests of quantum mechanics and gravity.

Contribution

It introduces a practical method to generate large superpositions of nano-objects with existing technology, advancing quantum experiments at macroscopic scales.

Findings

Large superpositions of 10^{-4} to 10^{-8} meters are achievable.

Masses of 10^{-16} to 10^{-14} kg can be superposed.

Superposition durations of up to 10 seconds are feasible.

Abstract

Probing quantum mechanics, quantum aspects of general relativity along with the sensing and the constraining of classical gravity can all be enabled by unprecedented spatial sizes of superpositions of massive objects. In this paper, we show that there is a feasible setup sourced by realizable magnetic field gradients ${\cal O}(10-100)$ Tm$^{-1}$ to construct a large spatial superposition of ${\cal O}(10^{-4}-10^{-8})$ m for masses ${\cal O}(10^{-16}-10^{-14})$ kg over a time period of up to $0.1-10$ seconds.