7 research outputs found
Understanding the Effect of Transpilation in the Reliability of Quantum Circuits
Transpiling is a necessary step to map a logical quantum algorithm to a circuit executed on a physical quantum machine, according to the available gate set and connectivity topology. Different transpiling approaches try to minimize the most critical parameters for the current transmon technology, such as Depth and CNOT number. Crucially, these approaches do not take into account the reliability of the circuit. In particular, transpilation can modify how radiation-induced transient faults propagate. In this paper, we aim at advancing the understanding of transpilation impact on fault propagation by investigating the low-level reliability of several transpiling approaches. We considered 4 quantum algorithms transpiled for 2 different architectures, increasing the number of qubits, and all possible logical-to-physical qubit mapping, adding to a total of 4, 640 transpiled circuits. We inject a total of 202, 124 faults and track their propagation. Our experiments show that by simply choosing the proper transpilation, the reliability of the circuit can improve by up to 14%
QuGAN: A Quantum State Fidelity based Generative Adversarial Network
Tremendous progress has been witnessed in artificial intelligence where
neural network backed deep learning systems have been used, with applications
in almost every domain. As a representative deep learning framework, Generative
Adversarial Network (GAN) has been widely used for generating artificial
images, text-to-image or image augmentation across areas of science, arts and
video games. However, GANs are computationally expensive, sometimes
computationally prohibitive. Furthermore, training GANs may suffer from
convergence failure and modal collapse. Aiming at the acceleration of use cases
for practical quantum computers, we propose QuGAN, a quantum GAN architecture
that provides stable convergence, quantum-state based gradients and
significantly reduced parameter sets. The QuGAN architecture runs both the
discriminator and the generator purely on quantum state fidelity and utilizes
the swap test on qubits to calculate the values of quantum-based loss
functions. Built on quantum layers, QuGAN achieves similar performance with a
94.98% reduction on the parameter set when compared to classical GANs. With the
same number of parameters, additionally, QuGAN outperforms state-of-the-art
quantum based GANs in the literature providing a 48.33% improvement in system
performance compared to others attaining less than 0.5% in terms of similarity
between generated distributions and original data sets. QuGAN code is released
at https://github.com/yingmao/Quantum-Generative-Adversarial-NetworkComment: 2021 IEEE International Conference on Quantum Computing and
Engineering (QCE
QuFI: a Quantum Fault Injector to Measure the Reliability of Qubits and Quantum Circuits
Quantum computing is a new technology that is expected to revolutionize the
computation paradigm in the next few years. Qubits exploit the quantum physics
proprieties to increase the parallelism and speed of computation.
Unfortunately, besides being intrinsically noisy, qubits have also been shown
to be highly susceptible to external sources of faults, such as ionizing
radiation. The latest discoveries highlight a much higher radiation sensitivity
of qubits than traditional transistors and identify a much more complex fault
model than bit-flip. We propose a framework to identify the quantum circuits
sensitivity to radiation-induced faults and the probability for a fault in a
qubit to propagate to the output. Based on the latest studies and radiation
experiments performed on real quantum machines, we model the transient faults
in a qubit as a phase shift with a parametrized magnitude. Additionally, our
framework can inject multiple qubit faults, tuning the phase shift magnitude
based on the proximity of the qubit to the particle strike location. As we show
in the paper, the proposed fault injector is highly flexible, and it can be
used on both quantum circuit simulators and real quantum machines. We report
the finding of more than 285M injections on the Qiskit simulator and 53K
injections on real IBM machines. We consider three quantum algorithms and
identify the faults and qubits that are more likely to impact the output. We
also consider the fault propagation dependence on the circuit scale, showing
that the reliability profile for some quantum algorithms is scale-dependent,
with increased impact from radiation-induced faults as we increase the number
of qubits. Finally, we also consider multi qubits faults, showing that they are
much more critical than single faults. The fault injector and the data
presented in this paper are available in a public repository to allow further
analysis
Quantum Computing Reliability: Problems, Tools, and Potential Solutions
Quantum computing is a new computational paradigm, expected to revolutionize the computing field in the next few years. Qubits, the atomic units of a quantum circuit, exploit the quantum physics properties to increase the parallelism and speed of computation. Unfortunately, qubits are both intrinsically noisy and highly susceptible to external sources of faults, such as ionizing radiation. The latest discoveries highlight a much higher radiation sensitivity of qubits than traditional transistors and identify a much more complex fault model than bit-flip. The observed error rate is so high that researchers are questioning the large-scale adoption of quantum computers. The reliability and dependability community is asked to act to find innovative solutions to improve the reliability of quantum applications. This tutorial aims at providing the DSN community with the tools to do so and to train the attendees on quantum fault injection