Topical Seminar: Multiparameter quantum metrology requires genuine high-dimensional entanglement

por Shuheng Liu (Peking University)

viernes 25 sept. 2026 11:00 → 12:00 Europe/Madrid

4-4-4426 - Seminari Física Teòrica (Campus Burjassot)

We establish uncertainty-like relations that directly bound the
sensitivity of physical parameters in terms of entanglement, revealing
that the maximum achievable sensitivity is fundamentally limited by
how much entanglement the system possesses. Entanglement—the
nonclassical correlations that link quantum systems—is a key
resource for quantum technologies, including precision measurements,
yet a central question has been how it constrains sensitivity, that
is, how sharply a quantum state responds to small changes in physical
parameters. Our framework answers this question and further
demonstrates that while simple, two-level entanglement is sufficient
for optimal estimation of a single parameter, genuinely
higher-dimensional entanglement becomes necessary when estimating
several parameters simultaneously. These findings deepen the
connections between quantum metrology and entanglement theory, with
potential applications in multiparameter sensing and the
characterization of complex quantum systems.