The Search for a New, Self-Correcting Phase of Matter

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A/Prof. David Poulin, Université de Sherbrooke

Is it possible, at least in principle, to design a quantum material that can sustain quantum information for very long times despite being in contact with a heat bath? For classical information storage, such materials are well-known and are used to build computers’ hard drives. The theory of fault-tolerant quantum error-correction shows that it is in principle possible to maintain a quantum state coherent for arbitrarily long times, but doing so requires active external intervention on the system. Thus, hard drives based on fault-tolerant error-correction would lose their information content as soon as the computer is switched off. In this talk I will review some of these concepts and provide evidence that self-correction is not possible in two spatial dimensions.