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Cureved lines indicate the superconducting cavity. Bottom-right is the switch. (via UCSB & Physical Review Letters)


As we continue to pave our way to a computer-optimized world, the quest for more processing speed and computing capacity is bundled right alongside the ultimate goal. Current computing components are beginning to reach the beginning stages of their physical limits, though Moore’s Law suggests that in a few years our computers will be operating on processors sized at the atomic level. Quantum computing coincides with this theory - a form of computing that will harness atoms and molecules to perform processing operations at speeds that trump silicon-based computation. Most work on quantum computing is still on the theoretical level, signaling that the technology is still years away. However, recent work by researchers at the University of California Santa Barbara that involves the manipulation of photons on a superconducting chip brings quantum-computing one-step closer to reality.


Quantum computers work by exploiting quantum mechanics through the adoption of qubits to transfer information over the traditional bit system. The quantum theory of superposition explains that a system existing in a single state can be considered to partly exist in two or more other states all at once. When the system is observed, a single “weighted-average” of the states is seen. What this means for computation is that qubits can store information in a 1 or a 0 state while existing in every other possible state at the same time. Thus, rather than reading and performing one process at a time, a quantum computer would be able to perform many calculations all at once.


One way of transferring quantum information through qubits would be performed through manipulation of photons. Physicists Yu Chen, Yi Yin, and Jim Wenner developed a superconducting chip that incorporates a superconducting cavity and switch that controls that movement of a photon. Yin first used classical electronics to drive photons into the -273.12 degree Celsius resonator area of the superconducting cavity. The switch was then used to quickly open and close a shutter that allowed the photons to move down the cavity toward an area where the photons can transmit. The flexibility of the shutter allowed the researchers to have complete control over the released waveforms of the photons. This finding is significant, as it would allow perfect transmission of information via qubit along a superconducting cavity.


The next step in the research is to work on transferring photons between distant cavities. Wenner hopes the work will provide safe and accurate transmission of quantum information over long distance - for example, remote quantum communication between satellites and devices on Earth.