Computers permeate all socio-economic activities of our times. The limitations of our present silicon-based computational power are no longer residing in the far future. The topic of this award is one that is relevant to finding new directions for future computation, while at the same time enlarging our understanding of physical systems suitable for quantum computing. The research will address fundamental science questions, such as whether topological states of matter can store, at non-zero temperatures, quantum (qubit) or classical (bit) elements of information. The research activities will be accompanied by educational efforts at three different levels: The PIs will provide solid education and training to graduate students in the field of quantum information; they will develop undergraduate courses at the interface between physics and computer science; and they will use their expertise to help develop the "Future of Information" module for techCAMP, a program directed towards middle-school and high-school teachers.
Encoding information in topological states of certain many-particle systems has been proposed as robust way to store quantum information. In these systems, the ground state is not unique and its multiplicity is not altered by local perturbations. As a result, when used to encode information, topological qubits are less susceptible to errors than standard qubits. Although protected from static perturbations, it is still uncertain how effective topological quantum memories are in the presence of dynamical perturbations. The proposed research addresses two important aspects of this issue. The first concerns the study of loss of coherence in realistic setups, where both equilibrium and non-equilibrium noise must be considered. The second is whether topological quantum memories in the presence of thermal fluctuations are attainable in physically realizable systems. Building on these investigations, the goal is to find ways to improve fault tolerance in topological quantum information processing.
