Fidelity estimation for quantum computing systems

A method for estimating quantum hardware fidelity, comprising;

• accessing quantum hardware, wherein the quantum hardware is configured to perform one or more different continuous Hamiltonian evolutions;
• selecting a particular continuous Hamiltonian evolution;
• performing the selected continuous Hamiltonian evolution of a quantum system and performing measurements on the quantum system to determine output information of the quantum system;
• calculating output information of the quantum system based on performing the selected continuous Hamiltonian evolution on the quantum system;
• and
• estimating a fidelity of the quantum hardware based on the determined output information and the calculated output information of the quantum system,

An apparatus comprising:

• quantum hardware comprising:
• one or more qubits;
• a universal set of one or more quantum gates;
• one or more measurement devices;
• one or more classical processors in data communication with the quantum hardware;
• wherein the quantum hardware and one or more classical processors are configured to perform operations comprising:
• sampling a plurality of subsets of quantum gates from the universal set of quantum gates, wherein each subset of quantum gates defines a respective quantum circuit;
• wherein each gate in the universal set of quantum gates is associated with a respective quantum gate fidelity and each sampled subset of quantum gates comprises a same number of quantum gates of comparable respective quantum gate fidelity;
• wherein, for each sampled subset of quantum gates, the quantum hardware and one or more classical processors are configured to:
• apply the quantum circuit to a quantum device and perform measurements on the quantum device to determine output information of the quantum device;
• calculate output information of the quantum device based on application of the quantum circuit to the quantum device;
• and
• estimate a fidelity of the quantum circuit based on the determined output information and the calculated output information of the quantum device.

An apparatus comprising:

• quantum hardware configured to perform continuous Hamiltonian evolution;
• one or more classical processors in data communication with the quantum hardware;
• wherein the quantum hardware and one or more classical processors are configured to perform operations comprising:
• selecting a particular continuous Hamiltonian evolution;
• performing the selected continuous Hamiltonian evolution of a quantum system and performing measurements on the quantum system to determine output information of the quantum system;
• calculating output information of the quantum system based on performing the selected continuous Hamiltonian evolution on the quantum system;
• and
• estimating a fidelity of the quantum hardware based on the determined output information and the calculated output information of the quantum system.