Results 71 to 80 of about 9,805 (195)
Photonic Metrology with Hierarchic Quantum Frequentist Bounds
Advanced Photonics Research, Volume 6, Issue 12, December 2025.This paper proposes photonic metrology with hierarchical quantum frequentist bounds. The present model tightens the Quantum Cramér‐Rao Bound using a hybrid classical‐quantum framework. The experiment validates the hierarchical frequentist bounds for single‐qubit phase estimation.
Xin‐Zhu Liu +6 more
wiley +1 more source
Morphophoric POVMs, generalised qplexes, and 2-designs [PDF]
Quantum, 2020 We study the class of quantum measurements with the property that the image of the set of quantum states under the measurement map transforming states into probability distributions is similar to this set and call such measurements morphophoric. This leads to the generalisation of the notion of a qplex, where SIC-POVMs are replaced by the elements of ...
Wojciech Słomczyński, Anna Szymusiak
openaire +4 more sources
Statistical Complexity of Quantum Learning
Advanced Quantum Technologies, Volume 8, Issue 12, December 2025.The statistical performance of quantum learning is investigated as a function of the number of training data N$N$, and of the number of copies available for each quantum state in the training and testing data sets, respectively S$S$ and V$V$. Indeed, the biggest difference in quantum learning comes from the destructive nature of quantum measurements ...
Leonardo Banchi +3 more
wiley +1 more source
Extremal covariant measurements
, 2006 We characterize the extremal points of the convex set of quantum measurements that are covariant under a finite-dimensional projective representation of a compact group, with action of the group on the measurement probability space which is generally non-
Chuang I. L. +5 more
core +2 more sources
Randomized Benchmarking beyond Groups
PRX Quantum, 2022 Randomized benchmarking (RB) is the gold standard for experimentally evaluating the quality of quantum operations. The current framework for RB is centered on groups and their representations but this can be problematic.
Jianxin Chen, Dawei Ding, Cupjin Huang
doaj +1 more source
Quantum‐Noise‐Driven Generative Diffusion Models
Advanced Quantum Technologies, Volume 8, Issue 12, December 2025.Diffusion Models (DMs) are today a very popular class of generative models for Machine Learning (ML), using a noisy dynamics to learn an unknown density probability of a finite set of samples in order to generate new synthetic data. This study proposes a method to generalize them into the quantum domain by introducing and investigating what are termed ...
Marco Parigi +2 more
wiley +1 more source
Linear Quantum State Observers
IEEE Transactions on Quantum Engineering, 2022 This article considers the use of linear state observers to infer the unknown state (density matrix) of a closed quantum system using generalized quantum measurement—positive operator-valued measures (POVMs). An efficient test for observability is
Maison Clouatre +3 more
doaj +1 more source
Is there contextuality for a single qubit?
, 2008 It was presented by Cabello and Nakamura [A. Cabello, Phys. Rev. Lett. 90, 190401 (2003)], that the Kochen-Specker theorem applies to two dimensions if one uses Positive Operator-Valued Measures.
A. Peres +6 more
core +1 more source
High-Fidelity, Multiqubit Generalized Measurements with Dynamic Circuits
PRX QuantumGeneralized measurements, also called positive operator-valued measures (POVMs), can offer advantages over projective measurements in various quantum information tasks. Here, we realize a generalized measurement of one and two superconducting qubits with
Petr Ivashkov +4 more
doaj +1 more source
Quantum Time and Quantum Evolution
Universe, 2023 The problem of quantum time and evolution of quantum systems, where time is not a parameter, is considered. In our model, following some earlier works, time is represented by a quantum operator.
Andrzej Góźdź +2 more
doaj +1 more source