99 citations · 490 across the 39 of their papers we have counts for
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Pure states are optimal for total energy-constrained quantum channel discrimination
Christos N. Gagatsos
We consider the discrimination of two quantum channels acting on bosonic modes, with a probe state of fixed mean photon number and no ancilla. We prove that pure probes are optimal…
Saturating the Bayesian Nagaoka-Hayashi bound within numerical precision for the depolarization SU(2) rotation channel
Leo Bia, Christos N. Gagatsos
The Bayesian Nagaoka--Hayashi (NH) bound is a semidefinite lower bound on the Bayes risk of multiparameter estimation, tighter than the Bayesian symmertic logarithmic derivative (S…
Optimal Probe State for Phase Estimation Under Covariant Measurement
Qipeng Qian, Christos N. Gagatsos
We study the optimization of input states for phase estimation under covariant measurements. Building on Holevo's framework, which provides the optimal covariant measurement for a…
GHZ is All You Need: Quantum Sensing with VISTA
Oskar Novak, Christos N. Gagatsos, Narayanan Rengaswamy
Quantum metrology holds the potential to enhance magnetic field sensing beyond current limits. However, in the presence of realistic noise, this advantage degrades to the Standard…
Upper bounds on the purity of Wigner positive quantum states that verify the Wigner entropy conjecture
Qipeng Qian, Christos Gagatsos
We present analytical results toward the Wigner entropy conjecture, which posits that among all physical Wigner non-negative states the Wigner entropy is minimized by pure Gaussian…