CQI seminar: Lorenzo Laneve
by William Schober
Dear friends,
On Monday 23.06 at 11:00 in D5.01 we'll have a talk by Lorenzo Laneve about quantum signal processing. Title and abstract below.
Join us in person or online at https://meet.jit.si/CQISeminarTalks
Best regards,
Will Schober
Speaker: Lorenzo Laneve
Title: An adversary bound for quantum signal processing
Abstract: Quantum signal processing (QSP) is a technique that revolutionized quantum algorithmic theory: many new and known quantum algorithms — amplitude amplification, Hamiltonian simulation, and phase estimation — can be rewritten as the application of a polynomial transformation to the eigenvalue or singular values of a matrix that is block-encoded (e.g. the top-left block) in a unitary. A central question is to understand which polynomials we can achieve with QSP, especially when we have multiple signals. For this work, we borrow tools from quantum query complexity, namely state conversion and the adversary bound: we show that QSP can be seen as an instance of state conversion over the Hilbert space L^2 of square-integrable functions. As a consequence, the adversary bound is a semidefinite program that identifies all the possible QSP protocols for a desired transformation, even in the case of multiple variables, which constitutes an operational way to compute and test the existence of such protocols.
1 month, 1 week
CQI seminar: Sophie Berthelette
by William Schober
Dear friends,
Today at 12:30 in D5.01, Sophie Berthelette will give an introductory seminar to the group.
Hope to see you there,
Will Schober
1 month, 2 weeks
CQI seminar: Razeen ud-Din
by William Schober
Dear friends,
Tomorrow at 2:30 in D5.01 we'll have a second talk by Razeen ud-Din from IBA Karachi, a follow-up to his talk last month on nonlocality distillation. Title and abstract below.
Best regards,
Will Schober
Title: Nonlocality Distillation for Mixed States
Description:
In the previous talk, we explored how nonlocality distillation outperforms entanglement concentration for pure states. In this presentation, we extend this investigation to mixed states. To frame this broader goal, we pause at a key intermediate question:
What does nonlocality distillation look like for multiple copies of a mixed state?
By addressing this question, we aim to better understand the power and limitations of nonlocality distillation in more realistic, noisy scenarios.
1 month, 2 weeks