Backends are the general term for the systems that process circuit jobs, both the physical quantum computers as well software simulators.

For the purposes of quantum software development, hardware and software backends are functionally interchangeable assuming the job in question falls within the capabilities of both backends, and the data is processed in the same fashion in both cases.


Backends

Characterization Data

A characterization is a snapshot of an IonQ QPU’s performance at a moment in time. While our quantum computers are continuously calibrated moment to moment, we periodically take measurements of gate fidelities and other statistics.

Current data is listed in the UI (Click on “Show Details” on a backend). Current and past characterizations are available via the API.

Status

The status of our systems can be found on status.ionq.co. The possible statuses are:

  • Operational: The system is meeting spec both in terms of job quality and throughput.
  • Degraded: The system is underperforming spec. The specific way it is underperforming will be noted on the status page.
  • Partial Outage: The system is down while a component is remotely reconfigured.
  • Major Outage: The system is down while two or more components are remotely reconfigured.
  • Under Maintenance: The system is down while one or more components are under physical maintenance.

Hardware

TypeNameAvailabilityIDQubitsLocation
HardwareForte Enterprise 1Availableqpu.forte-enterprise-136Basel, Switzerland
HardwareForte 1Availableqpu.forte-136College Park, MD
HardwareAria 1Availableqpu.aria-125College Park, MD
HardwareAria 2Availableqpu.aria-225College Park, MD
HardwareHarmonyRetiredqpu.harmony11College Park, MD

Simulators

All of our simulators are hosted on Google Cloud and can be accessed with the backend name simulator. See our Simulation with Noise Models guide for more information about our noise models and their usage.

TypeNameAvailabilityNoise ModelQubits
SimulatorIdealAvailableideal (default)29
SimulatorForte 1 Noise ModelAvailableforte-136
SimulatorAria 1 Noise ModelAvailablearia-125
SimulatorAria 2 Noise ModelAvailablearia-225
SimulatorHarmony Noise ModelAvailableharmony11
These qubit counts represent the upper limits for simulation jobs that can be submitted. Simulations approaching the ideal and Forte 1 qubit limits may still fail, depending on the specific circuit.