Exploring Einstein's theories of relativity in quantum systems, for example
by using atomic clocks at high speeds can deepen our knowledge in physics.
However, many challenges still remain on finding novel methods for detecting
effects of gravity and of special relativity and their roles in light-matter
interaction. Here we introduce a scheme of x-ray quantum optics that allows for
a millimeter scale investigation of the relativistic redshift by directly
probing a fixed nuclear crystal in Earth's gravitational field with x-rays.
Alternatively, a compact rotating crystal can be used to force interacting
x-rays to experience inhomogeneous clock tick rates in a crystal. We find that
an association of gravitational or special-relativistic time dilation with
quantum interference will be manifested by deflections of x-ray photons. Our
protocol suggests a new and feasible tabletop solution for probing effects of
gravity and special relativity in the quantum world.Comment: 17 pages, 4 figures, 1 table and Supplemental Material