Error Diagnostics

True-Q™ provides a wide variety of error diagnostic protocols to characterize quantum hardware that range from benchmarking of individual operations to benchmarking entire cycles and circuits.

Getting started

The following pages cover both the basic and advanced usage of True-Q™ protocols.

  1. Choosing the Appropriate Diagnostic Tool

    Outlines the basic types of protocols and helps the user get started with the diagnostic tools.

  2. Introduction to Protocols

    Provides a more in-depth introduction into how the error diagnostic protocols work in True-Q™.

  3. Selecting Parameters for Error Diagnostics

    Gives an overview of the simple input parameters to protocols and how their value affect the results.

  4. Selecting Parameters for Error Diagnostics (Advanced)

    Covers the full set of parameters for all diagnostic protocols.


True-Q™'s error diagnostic protocols are listed below. For each protocol, we provide the theoretical background alongside with a hands-on example that shows how to run the protocol in the software.

  1. Streamlined Randomized Benchmarking (SRB) and Example: Running SRB

    Estimates the average gate fidelity over the Clifford group acting on a subset of qubits.

  2. Interleaved Randomized Benchmarking (IRB) and Example: Running IRB

    Enhances SRB by estimating the average gate fidelity of specific gates, including error analysis that accounts for systematic effects.

  3. Extended Randomized Benchmarking (XRB) and Example: Running XRB

    Enables users to distinguish systematic (coherent) errors from stochastic errors (such as decoherence, dephasing, and rapid fluctuations in control frequencies) in combination with SRB. See Example: Comparing Infidelities with SRB and XRB for how these two protocols can be combined.

  4. Cycle Benchmarking (CB) and Example: Running CB

    A more practical alternative to SRB for multi-qubit systems that uses simpler randomizing gates, accommodates non-Clifford interleaved gates, and provides more fine-grained information about the noise.

  5. K-body Noise Reconstruction (KNR) and Example: Running KNR

    Systematically and efficiently reconstructs the action of the global error distribution on subsets of qubits.

Composite Protocols

Composite protocols leverage more basic diagnostic protocols to provide higher-level assessments of quantum hardware performance. True-Q™ currently contains two composite protocols:

  1. Crosstalk Diagnostics (CTD) and Example: Running CTD

    Measures the discrepancy between gate quality while applying gates simultaneously versus while applying gates in an isolated way to each individual subsystem.

  2. Quantum Capacity (QCAP) and Example: Estimating Quantum Capacity

    Provides a bound on the performance of a circuit performed under RC.