Most technologies today rely on devices that transport energy in the form of light, radio, or mechanical waves; however, these waveguiding channels are susceptible to disorder and damage, either in manufacturing or after they are deployed in harsh environments.
Researchers have experimentally demonstrated a new way to transport energy, even through waveguides that are defective and even if the disorder is a transient phenomenon in time. This work could lead to much more robust devices that continue to operate in spite of damage.
The work demonstrated a topological pump — a system that produces on-demand, robust transport of mechanical energy when it is periodically driven in time. The researchers built the topological pump using a one-dimensional, magnetomechanical, artificial material composed of springs, masses, and magnets.
The underlying principle is to make gradual, periodic modulations to the structure of the chain as a function of time. At the completion of each period of the pumping cycle, a single particle must enter the chain on one end and simultaneously, a single particle must exit the other end of the chain. This reliably occurs, even if the chain of atoms has some moderate amount of disorder.
This type of system is termed a pump because its technical description evokes a vision of an Archimedes Screw, a hand-cranked water pump dating back to ancient Egypt. The researchers’ pump transports mechanical energy, not particles or water, across the entire chain in one period of the pumping cycle. Moreover, the pump operates successfully even if the chain has a significant amount of disorder in space or time. To complete the analogy to a water screw pump, the researchers powered their demonstration with a rotating crank shaft.
Ultimately, the team would like to extend the demonstration to produce similarly resilient waveguides for light, sound, and electricity. The goal is to put a signal in on one end of a one-dimensional channel and have guaranteed transport to the other end in a robust fashion whenever the user wants it.
Optical fiber and copper lines form the backbone of communication technologies. Presently, moderate damage along such communication channels (e.g. anything but complete disconnection) can reduce signal strength and even produce undesirable reflections that adversely affect the amount of data these channels can carry. The team believes that topological pumping could be a solution in these scenarios.