# Efficient learning of quantum noise

@article{Harper2020EfficientLO, title={Efficient learning of quantum noise}, author={Robin Thomas Ross Harper and Steven T. Flammia and Joel Wallman}, journal={Nature Physics}, year={2020}, pages={1-5} }

Noise is the central obstacle to building large-scale quantum computers. Quantum systems with sufficiently uncorrelated and weak noise could be used to solve computational problems that are intractable with current digital computers. There has been substantial progress towards engineering such systems 1 – 8 . However, continued progress depends on the ability to characterize quantum noise reliably and efficiently with high precision 9 . Here, we describe such a protocol and report its… Expand

#### Paper Mentions

#### 63 Citations

Efficient Noise Mitigation Technique for Quantum Computing

- Computer Science, Physics
- ArXiv
- 2021

A novel protocol is proposed that efficiently estimates the average output of a noisy quantum device to be used for quantum noise mitigation and demonstrates improved accuracy with efficient noise characterization. Expand

Characterize noise correlation and enhance coherence via qubit motion

- Physics
- 2020

The identification of spacial noise correlation is of critical importance in developing error-corrected quantum devices, but it has barely been studied so far. In this work, we utilize an effective… Expand

Characterizing noise correlation and enhancing coherence via qubit motion

- Physics
- 2021

Abstract The identification of spacial noise correlation is of critical importance in developing error-corrected quantum devices, but it has barely been studied so far. In this work, we utilize an… Expand

Modeling and mitigation of cross-talk effects in readout noise with applications to the Quantum Approximate Optimization Algorithm

- Computer Science, Physics
- Quantum
- 2021

This work introduces a correlated measurement noise model that can be efficiently described and characterized, and which admits effective noise-mitigation on the level of marginal probability distributions, and finds that correlations in the measurement noise do not correspond to the physical layout of the device. Expand

Impact of correlations and heavy tails on quantum error correction

- Physics
- 2021

We show that spaceand time-correlated single-qubit rotation errors can lead to high-weight errors in a quantum circuit when the rotation angles are drawn from heavy-tailed distributions. This leads… Expand

Experimental Bayesian estimation of quantum state preparation, measurement, and gate errors in multi-qubit devices

- Physics
- 2021

We introduce a Bayesian method for the estimation of single qubit errors in a quantum devices and use it to characterize these errors on two 27-qubit superconducting qubit devices. We… Expand

Efficient Estimation of Pauli Channels

- Mathematics, Physics
- 2019

Pauli channels are ubiquitous in quantum information, both as a dominant noise source in many computing architectures and as a practical model for analyzing error correction and fault tolerance.… Expand

A Systematic Methodology to Compute the Quantum Vulnerability Factors for Quantum Circuits

- Computer Science
- ArXiv
- 2021

The Quantum Vulnerability Factor (QVF) is proposed as a metric to measure the impact that the corruption of a qubit has on the circuit output probability distribution, and guidelines on how to map the qubits in the real quantum computer to reduce the output error and to reduced the probability of having a radiation-induced corruption to modify the output. Expand

Quantum Overlapping Tomography.

- Physics, Medicine
- Physical review letters
- 2020

It is argued that with near-term experiments, every two-point correlator in a system of 1024 qubits could be measured and completely characterized in a few days, and shown that all k-qubit reduced density matrices of an n qubit state can be determined with at most e^{O(k)}log^{2}(n) rounds of parallel measurements. Expand

Quantum process tomography with unsupervised learning and tensor networks

- Computer Science, Physics
- 2020

A new technique for performing quantum process tomography is presented by combining a tensor network representation of the channel with a data-driven optimization inspired by unsupervised machine learning, providing a practical and timely tool for benchmarking quantum circuits in current and near-term quantum computers. Expand

#### References

SHOWING 1-10 OF 40 REFERENCES

Qubit metrology for building a fault-tolerant quantum computer

- Physics, Mathematics
- 2015

Recent progress in quantum information has led to the start of several large national and industrial efforts to build a quantum computer. Researchers are now working to overcome many scientific and… Expand

A blueprint for demonstrating quantum supremacy with superconducting qubits

- Physics, Medicine
- Science
- 2018

Nine superconducting qubits are used to demonstrate a promising path toward quantum supremacy and the scaling of errors and output with the number of qubits is explored in a five- to nine-qubit device. Expand

Noise tailoring for scalable quantum computation via randomized compiling

- Physics
- 2016

Quantum computers are poised to radically outperform their classical counterparts by manipulating coherent quantum systems. A realistic quantum computer will experience errors due to the environment… Expand

Characterizing large-scale quantum computers via cycle benchmarking

- Computer Science, Physics
- Nature Communications
- 2019

Quantum computers promise to solve certain problems more efficiently than their digital counterparts. A major challenge towards practically useful quantum computing is characterizing and reducing the… Expand

Randomized Benchmarking of Quantum Gates

- Computer Science, Physics
- 2007

A key requirement for scalable quantum computing is that elementary quantum gates can be implemented with sufficiently low error. One method for determining the error behavior of a gate… Expand

Experimental quantum compressed sensing for a seven-qubit system

- Physics, Medicine
- Nature communications
- 2017

This work presents an experimental implementation of compressed tomography of a seven-qubit system—a topological colour code prepared in a trapped ion architecture and argues that low-rank estimates are appropriate in general since statistical noise enables reliable reconstruction of only the leading eigenvectors. Expand

Experimental demonstration of Pauli-frame randomization on a superconducting qubit.

- Physics, Computer Science
- 2018

This work uses high-accuracy gate-set tomography to demonstrate that without randomization the natural errors experienced by this experiment have coherent character, and that with randomization these errors are rendered incoherent, and demonstrates how noise models can be shaped into more benign forms for improved performance. Expand

Extending the lifetime of a quantum bit with error correction in superconducting circuits

- Computer Science, Medicine
- Nature
- 2016

A QEC system that reaches the break-even point by suppressing the natural errors due to energy loss for a qubit logically encoded in superpositions of Schrödinger-cat states of a superconducting resonator is demonstrated. Expand

State preservation by repetitive error detection in a superconducting quantum circuit

- Computer Science, Physics
- Nature
- 2015

The protection of classical states from environmental bit-flip errors is reported and the suppression of these errors with increasing system size is demonstrated, motivating further research into the many challenges associated with building a large-scale superconducting quantum computer. Expand

Quantum computations on a topologically encoded qubit

- Computer Science, Medicine
- Science
- 2014

A quantum error-correcting code in which one qubit is encoded in entangled states distributed over seven trapped-ion qubits, which represents a fully functional instance of a topologically encoded qubit, or color code, and opens a route toward fault-tolerant quantum computing. Expand