Test of Nonlocal Energy Alteration between Two Quantum Memories

When two particles are spin entangled, one may exhibit behavior that suggests its spin can nonlocally influence the spin of the other. This implies that the energy of the latter particle can be altered by a nonlocal quantum correlation, without enabling any form of superluminal communication. This energy alteration, however, remains to be experimentally testified. To test this phenomenon, we construct an incomplete Mach-Zehnder interferometer utilizing two quantum memories. The Stokes photon generated by the quantum memories serves as the first particle, while the atomic excitation stored within the memories acts as the second particle. Our results demonstrate that if the de Broglie-Bohm interpretation is realistic, the trajectory of the Stokes photon can be nonlocally influenced by a slight probe of the atomic excitation. Conversely, the position of the atomic excitation, as well as the energy ℏω_{hf} it carries, can also be nonlocally altered by controlling the Stokes photon. These findings underscore the continued relevance of nonlocality in hidden variable theories, consistent with Bell's theorem and recent experimental validations, while making clear that such phenomena do not violate the principles of relativity.