IQI Seminar

Quantum computers are poised to radically outperform their classical counterparts by manipulating coherent quantum systems. A realistic quantum computer will experience errors due to the environment and imperfect control. When these errors are even partially coherent, they present a major obstacle to achieving robust computation. I will describe a method for introducing independent random single-qubit gates into the logical circuit in such a way that the effective logical circuit remains unchanged. This randomization tailors the noise into stochastic Pauli errors, leading to a dramatic improvement in worst-case error rates for satisfying the fault-tolerant threshold. Moreover, this technique is provably robust to inevitable variation in the errors over the gate sets.  Under this approach, perhaps most importantly,  the worst case error rate of the tailored noise for universal sets of gates can be directly and efficiently measured through a recent advance in randomized benchmarking protocols based on the dihedral group. Remarkably, this method enables the realization of fault-tolerant quantum computation under the error rates observed in recent experiments.

Joint work with Joel Wallman. arXiv:1512:01098