Although much of the press coverage of QIS is on quantum computing, experts generally divide QIS into four categories: sensing and metrology, communications, simulation, and computing (some combine simulation and computing). Each can be used for a variety of applications.
- Sensing and metrology—navigation, precise timekeeping, locating subterranean mineral deposits;
- Communications—generating quantum keys for encryption and enabling quantum-secure communications (interception destroys the communication and exposes the interceptor);
- Simulation—calculating the properties of materials such as high-temperature superconductors and modeling nuclear and particle physics; and
- Computing—performing some computations much faster, in some cases exponentially faster, than is possible using conventional high-performance computers.
In a February 11, 2020, memorandum, the White House stated that it intends to double non-defense QIS funding by 2022. The memorandum notes that the FY2021 budget recommendation would provide the National Science Foundation with a budget of $230 million and the Department of Energy Office of Science with $237 million for QIS, and an additional $25 million to DOE specifically to support quantum internet research.