Experimental witness for general relativistic effects in quantum mechanics

Over the past two decades, both experimental and theoretical research works have suggested the possibility of observing nonclassical gravitational effects by detecting gravitationally induced quantum correlations. Most existing proposals focus on center-of-mass interactions in mesoscopic systems within the Newtonian regime. In this essay, we explore a different approach by examining the gravitational interaction of angular momentum eigenstates in the post-Newtonian limit. This offers a novel way to test general relativistic phenomena in a low-energy quantum mechanical setting. We also discuss the potential advantages and challenges of this approach compared to other existing schemes.