Gravity Probe Spin: Prospects for measuring general-relativistic precession of intrinsic spin using a ferromagnetic gyroscope

TL;DR

This paper proposes an experimental method using ferromagnetic gyroscopes in orbit to measure relativistic precession effects on intrinsic electron spins, bridging quantum physics and general relativity.

Contribution

It introduces a novel approach to test relativistic spin precession using macroscopic ferromagnetic gyroscopes in space, which has not been previously explored.

Findings

Potential to measure frame dragging and geodetic precession effects.

Feasibility of using ferromagnetic gyroscopes for relativistic tests.

Implications for understanding quantum spin behavior in curved spacetime.

Abstract

An experimental test at the intersection of quantum physics and general relativity is proposed: measurement of relativistic frame dragging and geodetic precession using intrinsic spin of electrons. The behavior of intrinsic spin in spacetime dragged and warped by a massive rotating body is an experimentally open question, hence the results of such a measurement could have important theoretical consequences. Such a measurement is possible by using mm-scale ferromagnetic gyroscopes in orbit around the Earth. Under conditions where the rotational angular momentum of a ferromagnet is sufficiently small, a ferromagnet's angular momentum is dominated by atomic electron spins and is predicted to exhibit macroscopic gyroscopic behavior. If such a ferromagnetic gyroscope is sufficiently isolated from the environment, rapid averaging of quantum uncertainty via the spin-lattice interaction enables readout of the ferromagnetic gyroscope dynamics with sufficient sensitivity to measure both the Lense-Thirring (frame dragging) and de Sitter (geodetic precession) effects due to the Earth.