FQI – Special Quantum Technologies Seminar
Presented by the Florida Quantum Initiative
“A Logical Qubit Built from Dissipatively-Stabilized Schrödinger Cat Qubits”
Friday, April 18 at 11:15am
1000 Malachowsky Hall (NVIDIA Auditorium)
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Abstract
States in a quantum computer must stay coherent long enough to finish processing quantum algorithms. Most paradigms to realize a practical universal quantum computer require quantum error correction to increase the lifetime of logical states. Quantum error correction employs logical qubits encoded in larger Hilbert spaces to mitigate the effects of noise at the physical level. Most demonstrations of quantum error correction encode logical qubits in blocks of physical qubits, with logical error rates decreasing with the size of the block. However, increasing the size of the block increases the number of qubits, thereby increasing system cost. I will present Amazon’s effort to encode a logical qubit in fewer degrees-of-freedom, thereby reducing the size of the logical block. In this work, Schrödinger Cat Qubits are used as data qubits which themselves take advantage of quantum error correction at the single qubit level. Counterintuitively, this logical qubit harnesses dissipation, typically thought of as harmful to quantum states, to protect the cat qubits from bit-flip error. I will also discuss how a repetition code is used to correct for phase errors, while preserving the bit-flip lifetime. Finally, I will give an outlook for how these types of quantum systems make scaling to large quantum processors easier.
Biography
Matthew Matheny, PhD, helped found the Center for Quantum Computing at Amazon Web Services, where he managed the project for their first prototype quantum chip, Ocelot. He is currently the Device Team Manager for AWS CQC in Pasadena, CA, building the next-generation devices for their quantum hardware. Prior to joining AWS, he was a Staff Scientist at the California Institute of Technology (Caltech) where he explored a variety of scientific topics and innovative devices within photonic, nanomechanical, and superconducting platforms.