Probing novel out-of-equilibrium dynamics and new phases in quantum systems

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Traditionally, the study of condensed matter physics has concerned itself with investigations of the properties of materials in equilibrium. This very fruitful effort has resulted in the discovery and classification of many exotic quantum phases of matter such as superconductors, quantum Hall insulators, and more recently topological materials, all of which have potentially immense technological implications. More recently however, and bolstered with the advent of new technologies to artificially engineer and manipulate quantum matter (for simulating complex materials and quantum computing), a new line of questioning focussed on properties of quantum matter out of equilibrium has gained impetus. In conventional materials, electrons are coupled to vibrations of the lattice, impurities and other sources of dissipation. As a result, they exchange energy and momentum with these sources of noise and equilibrate rapidly on nanosecond timescales. Thus, investigating quantum dynamics and out-of-equilibrium properties is extremely challenging in conventional materials. However, for a quantum simulator or computer to function as desired, it is absolutely necessary that it is immune to such decoherence. Today, a number of extremely promising candidates for quantum computing exist, each of which is isolated from noise to different degrees and has its own challenges. These include defects in diamond, atoms cooled to nano Kelvin temperatures in magnetoelectric traps, quantum bits engineered using superconducting junctions, and so on. To make further progress in using these devices to fulfill the challenges and promises of quantum computing, we need to understand precisely how quantum matter behaves in non-equilibrium settings. Can quantum matter be protected, somehow, from sources of noise and decoherence? Do all quantum systems thermalize by themselves, even in the absence of external noise, and if not all, what are the conditions that engender long-time non-equilibrium behavior? How can one find solutions to problems impossible to solve on a classical computer using quantum simulators? Can one induce favorable properties in quantum systems that would otherwise be impossible to find in equilibrium? Is there a classification of matter out-of-equilibrium as there is for matter in equilibrium? Finally, how can one probe such non-equilibrium behavior experimentally; in particular, what protocols can be devised to measure such properties? Our research is centered around solving precisely such problems which occur at the intersection of being practically relevant questions pertaining to the advancement of quantum simulators, and which have the potential to theoretically advance our knowledge of quantum non-equilibrium physics. We will deploy novel analytical and state-of-the-art numerical techniques, and work closely with experimental groups around Canada and globally to make progress on these problems.