A rich seam of technological and science-fictional ideas seem ready to be mined with the development of the first light trap that can simultaneously store different numbers of photons:
“These superposition states are a fundamental concept in quantum mechanics, but this is the first time they have been controllably created with light,” Cleland said. Martinis added, “This experiment can be thought of as a quantum digital-to-analog converter.” As digital-to-analog converters are key components in classical communication devices (for example, producing the sound waveforms in cell phones), this experiment might enable more advanced communication protocols for the transmission of quantum information.
The research is funded by IARPA. Intelligence services are understandably keen to learn more about the potential for quantum computers to break conventionally encrypted communications.