Verification methods for surface code implementations in superconducting systems

The surface code is a promising error-correction protocol for realizing large-scale quantum computation in superconducting qubit systems. Multi-qubit states and processes have recently been implemented with high enough fidelities in these systems to realize small building blocks of the surface code. We will discuss various metrics and tomographic protocols that can be used to characterize the performance of these building blocks and present recent experimental results that demonstrate high fidelity implementations in superconducting systems. Moving forward, these techniques will be useful for characterizing more complex surface code implementations, as well as more general error-correction strategies.