Prof. Fernando Brandao
Head - Quantum Algorithms, Amazon Web Services, California Institute of Technology.
30th October 2024, 9:30am - 10:30am (GST)
| Title: | Hardware-efficient quantum error correction using concatenated bosonic qubits |
| Location: | Indoors Arena, Masdar Office |
| Abstract: | In order to solve problems of practical importance, quantum computers will likely require error correction which encodes fault-tolerant logical qubits into many noisy physical qubits. The large overheads projected for achieving fault-tolerant quantum computers motivate the search for more hardware-efficient platforms error-correction strategies. A promising direction to reduce the error correction overhead is to employ bosonic qubits, formed by states of a bosonic mode. I will discuss an experimental realization of a logical qubit at the AWS Center for Quantum Computing. We built a superconducting circuit which implements a repetition code up to distance five of cat qubits stabilized in bosonic modes. Phase-flip errors on the data cat qubits are corrected by the repetition code using ancilla transmons. The cat qubits are passively protected against bit-flip errors by two photon dissipation and all the operations needed for error correction, including the controlled-not gate, retain a bias against bit-flip errors. Our experiment is the first to leverage built-in bosonic error correction in concert with an outer concatenated code and biased noise. |
| Bio: | Fernando Brandão is the head of quantum algorithms at Amazon Web Services (AWS) and the Bren Professor of Theoretical Physics at Caltech. He is a world-wide authority in quantum information and computation theory; and his research extends across quantum physics, information theory, and computer science. Prof. Brandão's science and technology journey includes notable stints at Google's Quantum AI Lab, Microsoft, University College London, ETH, and UFMG, all underpinned by a PhD from Imperial College London and postdoctoral fellowships at Imperial College London and UFMG. In 2009, he received the IoP Quantum Electronics and Photonics PhD Thesis Prize. In 2020, in turn, he was awarded the Rolf Landauer and Charles H. Bennett Award in Quantum Computing “for outstanding achievements in entanglement theory and in the intersection of quantum computation, quantum thermodynamics, and quantum many-body physics”. Besides that, he has also made major contributions to quantum cryptography, quantum Hamiltonian complexity, and quantum supremacy demonstrations. |