Atom interferometer

A spatially dependent potential or a local interaction differentiates the paths, introducing a phase difference between waves.

[10] The largest physical separation between the partial wave packets of atoms was achieved using laser cooling techniques and stimulated Raman transitions by Steven Chu and his coworkers in Stanford University.

The de Broglie wavelength of the incident beam was about 2.5 pm, whereas the diameter of the molecule is about 1 nm, about 400 times larger.

[13] In 2003, the Vienna group also demonstrated the wave nature of tetraphenylporphyrin[14]—a flat biodye with an extension of about 2 nm and a mass of 614 Da.

[14] Large molecules are already so complex that they give experimental access to some aspects of the quantum-classical interface, i.e., to certain decoherence mechanisms.

[20] The 2008 comprehensive review by Alexander D. Cronin, Jörg Schmiedmayer, and David E. Pritchard documents many new experimental approaches to atom interferometry.

[22][23] A precise measurement of gravitational redshift was made in 2009 by Holger Muller, Achim Peters, and Steven Chu.

[24] In 2020, Peter Asenbaum, Chris Overstreet, Minjeong Kim, Joseph Curti, and Mark A. Kasevich used atom interferometry to test the principle of equivalence in general relativity.