Summary
The overall goal of the project is to develop practical methods to be able to reliably run useful applications on near-term quantum computers. This requires identifying and overcoming the ubiquitous errors that currently limit quantum computing capabilities. Traditional methods of quantifying errors in quantum computers fail to predict how errors affect the output of a quantum computation because the exact impact depends upon the exact form of the noise, additional errors arising from interactions between control mechanisms (e.g., crosstalk) and idle qubits, and how the gates are translated and scheduled into temporal pulses. One promising way to account for global errors is to define a parallel quantum instruction (PQI) to be a set of quantum operations executed in a fixed temporal order, including all idle gates for qubits that are not explicitly targeted by any quantum operation. In this project we develop a general method for reconstructing global noise during a cycle of parallel quantum gates and a framework for mitigating and/or extrapolating errors, leading to an experimental demonstration of their effectiveness. This will enable near-term quantum computers to be used to accurately simulate quantum systems and to determine the accuracy of the simulations.

Figure 1. Schematic circuit implementation of the experimental cycle benchmarking protocol for characterizing a noisy parallel quantum instruction G (red). The green gates are used to probe how closely G maps different input states to the desired output state. Random gates (blue) are used to engineer a simple noise model to make the characterization protocol accurate and efficient.
Related Content

Extensible Technology for a Medium-Scale Superconducting Quantum Processor
Summary Superconducting quantum bits, or qubits, use circuits made from superconducting materials to harness quantum mechanical states. These devices contain many atoms, but can behave as simple, controllable qubits. We are building technologies for the control and measurement of superconducting qubits to enable the first demonstration of an extensible, medium-scale quantum processor. Our approach […]
November 28, 2016

Spin Generation and High-Frequency Detection via the Quantum Nonlinear Anomalous Hall Effect in Weyl Semimetals
In magnetic conductors, the passage of current yields an electric field in the transverse direction even without an external magnetic field – this is known as the anomalous Hall effect (AHE). This effect can act as a convenient probe of spin ordering, magnetic textures, spin-orbit coupling, and band topology in solids, and can be further […]
April 19, 2023

Tuning Spin-Exchange Interactions in Low-Dimensional Metal Halide Perovskites: A New Class of Semiconductor Quantum Materials
Summary Leakage current in electronic components is one of the limiting factors for the performance of conventional computers which use charges and currents as physical information carriers. Spintronics offers an alternative by using electron spin for information transfer, processing and storage, enabling the design of non-volatile computer memory and more energy-efficient electronic devices. In this […]
October 1, 2019
Using Interactive Digital Storytelling to Represent Transformative Quantum Technologies in Augmented/Extended Reality Environments
Summary A major roadblock to the broader adoption of quantum technologies is the long learning curve associated with their seemingly abstract concepts. This often renders quantum technologies inaccessible to most audiences, especially through explanations using conventional scientific language. In this project, we develop novel methods of interactive digital storytelling – augmented and extended reality (AR/XR) […]
February 24, 2021