We live in the information age. Information transmission and processing industries account for more than a quarter of the world’s economy. Information is ultimately based on a physical medium. Just as quantum physics has revolutionized our understanding of matter in the twentieth century, quantum physics has the potential to revolutionize the processing, transmission, and even the nature of information in the twenty-first century.
The classical elementary unit of information (or bit) is a physical system that can exist in two well-defined macroscopic states. Its quantum equivalent (or qubit) is a physical system that can exist in two different quantum states, or in a superposition of these two states. This ability to superimpose states in quantum physics means that a qubit can be both true and false; some algorithms use this ability to accelerate tasks exponentially, far beyond what a conventional computer could ever accomplish.
This promise is accompanied by immense but realistic challenges, both in the construction of physical qubits that can maintain their superimposed state in a constantly disruptive environment, in the design of systems that allow for the assembly and control of qubits, and in the design of robust algorithms that can withstand the inevitable imperfections of these systems. Not only is this new field of physics highly technologically promising, but it has stimulated a renewal in the study of the foundations of quantum mechanics and quantum effects at the macroscopic scale.
The Institut quantique has earned an enviable reputation worldwide in this young and growing field. Three laboratories are dedicated to the processing or control of quantum information in a very low temperature environment (a few thousandths of a degree above absolute zero). Theoretical researchers are engaged in the design of qubit-based systems, the design of robust quantum algorithms and numerical methods to study systems with a large number of qubits.