Programming a Quantum Computer with Quantum Instructions (Part 2): Demonstration and Characterization*

The equivalence between the instructions used to define programs and the input data on which the instructions operate is a basic principle of classical computer architectures and programming. However, in all previously-realized quantum computing models, quantum data have been transformed by a set of gates that are compiled using solely classical information. In this work, we execute a quantum program – density matrix exponentiation (DME) – that uses quantum instructions to process quantum data. In Part 2 of this talk, we benchmark an implementation of the DME algorithm in a two-qubit system. We demonstrate that the unitary implemented by DME depends uniquely on a quantum instruction state. We then explore tradeoffs between algorithmic error and coherence limitations in a noisy quantum processor, and characterize DME process via process tomography.