The work of this year’s Nobel Laureates not only proved that quantum theory reflected the real world, but they created an entirely new way to look at information processing. Quantum information science uses entangled bits to compute, sense, and transmit information more efficiently—which could be encrypted financial transactions, or astronomical observations, or medical images used in diagnosing cancer.
Quantum computers exploit the quantum-mechanical nature of photons, electrons, or atoms to process information that can vastly outperform today’s computers on certain tasks. These tasks include simulating complex molecules enabling drug discovery, recognizing patterns in large data sets, certain planning/scheduling challenges… and breaking most currently-available forms of encryption. Quantum sensors use exquisitely calibrated devices to sense tiny changes in signals with much finer resolution than can be achieved with classical devices. Such signals may include light collected by a microscope examining biological tissue, the magnetic field created by neuronal activity in a human brain, or photons from distant galaxies collected by a telescope. Quantum networks endeavor to connect large combinations of quantum computers and quantum sensors using communication channels that can transmit quantum bits, in a robust way over long distances. The quantum information will be encoded into photons and transmitted over optical fibers or through free space — either over centimeters (inside a computer), meters (inside a data center), kilometers (a metro area), or thousands of kilometers (continental or intercontinental).
Quantum information science is a two-edged sword. On one hand, quantum computers raise the possibility of quickly and economically breaking most common encryption mechanisms, which underpin everything from banking to medical records to navigation to cryptocurrencies. On the other hand, quantum networks promise an inherently-secure communications mechanism that will allow the safe transmission of information, even when attacked by adversaries with quantum computers. Networks based on quantum entanglement will initially be used for high-value information security applications. But as the technology becomes more cost effective, the applications will spread to a variety of uses, including improved navigation, long-baseline astronomy, medical imaging, and distributed quantum computation. Eventually, a widespread network of quantum computers, quantum sensors, and quantum networking devices acting together will enable applications which are difficult to imagine today.