Universal Fault-Tolerant Quantum Computation Across Stabilizer Codes

🍕 6:00–6:15 PM – Pizza & Social
🧠 6:15–7:15 PM – Presentation
🍻 7:15–7:45 PM – Social

Description
Fault-tolerant quantum computation enables quantum computations to be carried out while resisting unwanted noise, but implementing a universal logical gate set remains a challenge. Stabilizer codes provide robust error protection, but each code supports only a limited family of native fault-tolerant logical gates, requiring additional techniques—such as code concatenation, code switching, or magic state distillation—to access non-native operations. These techniques can be costly, nondeterministic, and often tailored to specific codes or architectures.

In this talk, we present a stabilizer code-generic framework for universal fault-tolerant quantum computation based on ancilla mediation: ancillary registers are used strictly for communication and gate transformation without storing data themselves. By leveraging helper codes—most notably the generalized Shor code and its Hadamard dual—along with mid-circuit measurements, the framework enables deterministic implementations of logical Clifford and T gates that do not consume ancilla registers and do not modify the underlying data code or register. We will outline the key constructions (including controlled-flip primitives, stabilizer-generic Hadamards, and Z-rotations), discuss validation and resource overhead considerations, and highlight how stabilizer-generic gates enable communication between heterogeneous stabilizer encodings.

Speaker
Nicholas Papadopoulos grew up in Avon, CT and received a B.A. in computer science at Boston University in 2016. He worked professionally as a software engineer in the fields of bioinformatics, high-security transportation, and quantum computing/networking before pursuing higher education at the University of Colorado Boulder in 2021. He is currently a research assistant in the computer science department at the University of Colorado Boulder with interests in quantum computing algorithms. He is the author of a paper describing a protocol to increase eavesdropping detection during quantum key distribution, increasing cryptography security, as well as a paper describing a family of algorithms containing Ramsey interferometry and Quantum Phase Estimation, bridging the gap between these two seemingly distinct algorithms.