2 research outputs found
Demonstration of quantum brachistochrones between distant states of an atom
Transforming an initial quantum state into a target state through the fastest
possible route---a quantum brachistochrone---is a fundamental challenge for
many technologies based on quantum mechanics. Here, we demonstrate fast
coherent transport of an atomic wave packet over a distance of 15 times its
size---a paradigmatic case of quantum processes where the target state cannot
be reached through a local transformation. Our measurements of the transport
fidelity reveal the existence of a minimum duration---a quantum speed
limit---for the coherent splitting and recombination of matter waves. We obtain
physical insight into this limit by relying on a geometric interpretation of
quantum state dynamics. These results shed light upon a fundamental limit of
quantum state dynamics and are expected to find relevant applications in
quantum sensing and quantum computing.Comment: 6 pages, 3 figures, and supplemental materia