Since the mid-1960s, we have been living in a world governed by Moore’s Law. In 1965, Intel co-founder Gordon Moore predicted that the number of transistors on computer chips would double every year—a trend that implied a yearly doubling of computer power. Later the predicted interval was amended to eighteen months. That prediction has held true for better than five decades as millions and eventually billions of transistors were crammed onto the most advanced computer chips. But given the sheer physical limits of miniaturization, Moore’s Law is now slowing down, and it has long been recognized that eventually Moore’s Law will come to an end.
That is one major development that has driven the growing interest in quantum information science (QIS)—forms of computing and information processing that might get around these “classical” physical limitations by relying on exotic quantum effects.
Such effects include “superposition”—whereby a quantum system can exist in all possible states until it is observed—and “entanglement”—whereby measurement of one member of a paired system causes the other member immediately to assume a related value, no matter how distant they are in space.
QIS is thought to have promise in three major areas:
Quantum computing. Rather than relying on bits with the value of 1 or 0, quantum computing uses qubits, which can exist at intermediate values. Quantum computers, while not a substitute for classical computers, are believed to be extraordinarily powerful at solving certain problems, such as the factoring of very large numbers and tackling some of the long-standing challenges in science. It is believed they would be especially apt at simulating actual physical quantum behavior, whether in material or chemical systems.
Quantum communication. Quantum information systems hold out the possibility of extremely secure encryption—a major attraction in an age where cybersecurity is constantly at risk.
Quantum sensing. It is believed that sensors based on quantum effects could be exquisitely sensitive and could aid in understanding everything from biological systems to the nature of dark matter.
Quantum foundational science. Fundamental theoretical and experimental research is needed to augment the application of QIS to quantum computing, communications, and sensing.
Recognizing these opportunities, and also aware of the growing international competition in this promising new area of science and technology, Congress passed the National Quantum Initiative Act, which became law in December 2018.
The DOE Office of Science is an integral partner in the National Quantum Initiative and has launched a range of multidisciplinary research programs in QIS. The efforts cut across the six major program offices within the Office of Science. They include efforts to develop quantum computers as testbeds, to design new algorithms for quantum computing, and to use quantum computing to model fundamental physics, chemistry, and materials phenomena. There is research relating the latest advances in string theory and black hole physics to quantum error correcting codes. There are efforts supporting quantum communication using entanglement towards the possible development of a future quantum network. There are also efforts in materials and chemical sciences to develop systems that will sustain performance, so-called “quantum coherence,” for significant periods of time—a prerequisite for effective quantum computing and information processing. In addition, there is work on sensors for next-generation detectors and the characterization tools that could enable the next round of innovations in science and engineering.