Amazon Web Services was last heard on the subject of quantum computing in December when it expanded the roster of quantum processors available through the service, but last week the AWS Quantum Computing Blog told the story of how two different research groups in Poland have been using the AWS’ Amazon Braket cloud quantum computing service to advance their projects.
One of those projects is focused on error mitigation for quantum computing. The Quantin Research Group, led by Professor Michał Oszmaniec at the Center for Theoretical Physics at the Polish Academy of Sciences, is developing computationally-efficient methods to study and mitigate the effects of noise and cross-talk during the measurement process in superconducting qubits, which is one of the top sources of errors in current quantum devices as they attempt to tackle more practical applications.
“Measurement errors in superconducting quantum devices can be, to a good approximation, modeled by classical stochastic maps.”, explained Oszmaniec, according to the blog post. “With Amazon Braket, we are able to apply recently-developed techniques to learn the structure of stochastic noise. We want to determine the type and magnitude of cross-talk in readout noise and are investigating an algorithm for grouping qubits into clusters exhibiting significant cross-talk. We then employ the obtained noise model in various readout error-mitigation schemes and study their dependence on the adopted noise model. Experiments so far have greatly improved our understanding of the structure of correlated measurement noise on the Rigetti Aspen-9 quantum processor. We hope further experiments will allow us to devise a comprehensive and scalable framework for measurement characterization and error mitigation applicable to even larger quantum computers.”
Another team at the Faculty of Cybernetics of the Military University of Technology in Warsaw, led by Dr. Krzysztof Kanciak, is investigating the application of quantum computers to the cryptographic security of common ciphers at a time when many governments and industries around the world are trying to better understand the security threat posed by quantum.
Kanciak is working on a proof-of-concept implementation of a prototypical block cipher attack. The team is investigating how to implement a quantum version of the Known-Plaintext Attack (KPA) on a toy version of the ARX cipher ‘Speck’ with a 4-bit block size, a 2-bit word/key size, and two encryption rounds. Determining the complexity of this style of quantum attack is crucial for understanding the threats to the security of symmetric cryptography, and for developing post-quantum cryptography schemes that are more secure, according to the blog post.
Another interesting aspect of both these projects is that they were enabled by the AWS Cloud Credit for Research Program, which researchers can apply for to help off-set the cost of using Amazon Braket quantum computing-as-a-service. Helping users handle the expense of using such cloud-based quantum programs will continue to be very important in the years to come, opening the doors for advances and innovations that otherwise might remain on the chalkboard due to their cost.