Truly relativistic gravity mediated entanglement protocol using superpositions of rotational energies

Experimental proposals for testing quantum gravity-induced entanglement of masses (QGEM) typically involve two interacting masses which are each in a spatial superposition state. Here, we propose instead a QGEM experiment with two particles which are each in a superposition of rotational states; this amounts to a superposition of mass through mass-energy equivalence. In sharp contrast to the typical protocols studied, our proposal is genuinely relativistic. It does not consider a quantum positional degree of freedom and but relies on the fact that rotational energy gravitates: the effect we consider disappears in the <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mi>c</a:mi><a:mo stretchy="false">→</a:mo><a:mi>∞</a:mi></a:math> limit. Furthermore, this approach would test a feature unique to gravity since it amounts to sourcing a spacetime in superposition due to a superposition of “charge.” Published by the American Physical Society 2024