6 papers
Geometric obstructions to quadratic time scaling in multiparameter quantum estimation
Eoin O'Connor, Jiayu He, Matteo G. A. Paris +1
Unitary encoding of a single parameter provides quadratic enhancement in precision, with the quantum Fisher information scaling quadratically with the encoding time. However, when…
Fisher geometry reshapes the effect of incompatibility in multiparameter quantum estimation
Jiayu He, Matteo G. A. Paris
Multiparameter quantum estimation faces two fundamental obstacles: sloppiness, i.e., anisotropy of the quantum Fisher information matrix (QFIM) that renders some parameter directio…
Orders matter: tight bounds on the precision of sequential quantum estimation for multiparameter models
Gabriele Fazio, Jiayu He, Matteo G. A. Paris
In multiparameter quantum metrology, the ultimate precision of joint estimation is dictated by the Holevo Cramér-Rao bound. In this paper, we discuss and analyze in detail an alte…
Weight-dependent and weight-independent measures of quantum incompatibility in multiparameter estimation
Jiayu He, Gabriele Fazio, Matteo G. A. Paris
Multiparameter quantum estimation faces a fundamental challenge due to the inherent incompatibility of optimal measurements for different parameters, a direct consequence of quantu…
Scrambling for precision: optimizing multiparameter qubit estimation in the face of sloppiness and incompatibility
Jiayu He, Matteo G. A. Paris
Multiparameter quantum estimation theory plays a crucial role in advancing quantum metrology. Recent studies focused on fundamental challenges such as enhancing precision in the pr…
Cartan Quantum Metrology
Gabriele Fazio, Jiayu He, Matteo G. A. Paris
We address the characterization of two-qubit gates, focusing on bounds to precision in the joint estimation of the three parameters that define their Cartan decomposition. We deriv…