Towards scalability and fault tolerance in continuous-variable quantum computation
Before they can be useful, quantum computers must be made large and robust to noise. I will discuss progress towards both requirements in the context of continuous-variable quantum information, where the data registers are Bosonic modes, such as spatial/temporal modes in quantum optics, or microwave resonator modes in superconducting qubit architectures. I will report on a recent experiment that deterministically generated large-scale quasi-two-dimensional resource states for measurement-based quantum computing. I will also discuss the key challenges to using such states for quantum computation: the effects of limited squeezing and the requirement of a non-Gaussian operation. Fortunately, one can address both issues in one fell swoop: encoded qubits known as Gottesman-Kitaev-Preskill (GKP) states allow for universal quantum computing with a constant squeezing overhead in the entangled resource state, and simultaneously provide the necessary non-Gaussianity for universal quantum computation.