Antihydrogen Gravitational Quantum States

TL;DR

This paper theoretically investigates antihydrogen atoms in Earth's gravity, predicting long-lived quantum states above surfaces and proposing spectroscopic methods to measure gravitational effects on antimatter, aiding tests of the Weak Equivalence Principle.

Contribution

It introduces a novel quantum state framework for antihydrogen in gravity and proposes spectroscopic experiments to measure antimatter's gravitational interaction.

Findings

Antihydrogen can form long-lived gravitational quantum states.

Spectroscopy can be used to measure energy differences in these states.

Potential to test the Weak Equivalence Principle with antimatter.

Abstract

We present a theoretical study of the motion of the antihydrogen atom ($\bar{H}$) in the Earth's gravitational field above a material surface. We predict that $\bar{H}$ atom, falling in the Earth's gravitational field above a material surface, would settle in long-living quantum states. We point out a method of measuring the difference in energy of $\bar{H}$ in such states that allow us to apply spectroscopy of gravitational levels based on atom-interferometric principles. We analyze a general feasibility to perform experiments of this kind. We point out that such experiments provide a method of measuring the gravitational force ($Mg$) acting on $\bar{H}$ and they might be of interest in a context of testing the Weak Equivalence Principle for antimatter.