English
Related papers

Related papers: Exact Steering Bound for Two-Qubit Werner States

200 papers

The discrimination of quantum states is a central problem in quantum information science and technology. Meanwhile, partial post-selection has emerged as a valuable tool for quantum state engineering. In this work, we bring these two areas…

Quantum Physics · Physics 2026-04-14 Qipeng Qian , Christos N. Gagatsos

In many a traditional physics textbook, a quantum measurement is defined as a projective measurement represented by a Hermitian operator. In quantum information theory, however, the concept of a measurement is dealt with in complete…

Quantum Physics · Physics 2015-11-06 Ravi Kunjwal , Chris Heunen , Tobias Fritz

Adopting the geometric description of steering assemblages and local hidden states (LHS) model, we construct the optimal LHS model for some two-qubit states under continuous projective measurements, and obtain a sufficient steering…

Quantum Physics · Physics 2018-12-05 Bai-Chu Yu , Zhih-Ahn Jia , Yu-chun Wu , Guang-Can Guo

Von Neumann measurement framework describes a dynamic interaction between a target system and a probe. In contrast, a quantum controlled measurement framework uses a qubit probe to control the actions of different operators on the target…

Quantum Physics · Physics 2020-06-03 Le Bin Ho

Positive operator valued measurements (POVMs) play an important role in efficient quantum communication and computation. While optical systems are one of the strongest candidates for long distance quantum communication and information…

Quantum Physics · Physics 2022-01-19 Jaskaran Singh , Arvind , Sandeep K. Goyal

Similarly to quantum states, also quantum measurements can be "mixed", corresponding to a random choice within an ensemble of measuring apparatuses. Such mixing is equivalent to a sort of hidden variable, which produces a noise of purely…

Quantum Physics · Physics 2007-05-23 Giacomo Mauro D'Ariano , Paoloplacido Lo Presti , Paolo Perinotti

We characterize the asymptotic performance of a class of positive operator valued measurements (POVMs) where the only task is to make measurements on independent and identically distributed quantum states on finite-dimensional systems. The…

Quantum Physics · Physics 2016-11-24 Janis Nötzel

Unsharp POVM measurements allow the estimation and tracking of quantum wavefunctions in real-time with minimal disruption of the dynamics. Here we demonstrate that high fidelity state monitoring, and hence quantum control, is possible even…

Quantum Physics · Physics 2015-06-03 T. Konrad , H. Uys

We theoretically describe the weak measurement of a two-level system (qubit) and quantify the degree to which such a qubit measurement has a quantum non-demolition (QND) character. The qubit is coupled to a harmonic oscillator which…

Mesoscale and Nanoscale Physics · Physics 2015-05-13 Luca Chirolli , Guido Burkard

How much unavoidable randomness is generated by a Positive Operator Valued Measure (POVM)? We address this question using two complementary approaches. First we study the variance of a real variable associated to the POVM outcomes. In this…

Quantum Physics · Physics 2011-06-03 Serge Massar

In quantum mechanics the statistics of the outcomes of a measuring apparatus is described by a positive operator valued measure (POVM). A quantum channel transforms POVM's into POVM's, generally irreversibly, thus loosing some of the…

Quantum Physics · Physics 2007-05-23 F. Buscemi , G. M. D'Ariano , M. Keyl , P. Perinotti , R. Werner

To mitigate dissipative effects from environmental interactions and efficiently stabilize quantum states, time-optimal control has emerged as an effective strategy for open quantum systems. This paper extends the framework by incorporating…

Quantum Physics · Physics 2025-08-25 Yunyan Lee , Ian R. Petersen , Daoyi Dong

In this article, we introduce a numerical framework for quantum tomography and entanglement quantification of three-qubit generalized Werner states. The scheme involves the single-qubit SIC-POVM, which is then generalized to perform…

Quantum Physics · Physics 2022-07-20 Artur Czerwinski

We study the local implementation of POVMs when we require only the faithful reproduction of the statistics of the measurement outcomes for all initial states. We first demonstrate that any POVM with separable elements can be implemented by…

Quantum Physics · Physics 2007-05-23 S. Virmani , M. B. Plenio

Various forms of optimality for quantum observables described as normalized positive operator valued measures (POVMs) are studied in this paper. We give characterizations for observables that determine the values of the measured quantity…

Quantum Physics · Physics 2018-09-28 Erkka Haapasalo , Juha-Pekka Pellonpaa

Constructing an integrated large-scale qubit system of realistic size requires addressing the challenge of physical crowding among qubits. This constraint poses an issue of coarse-grained (CG) measurement, wherein information from the…

Quantum Physics · Physics 2024-04-10 Donghun Jung , Young-Wook Cho , Yosep Kim , Junghyun Lee

Quantum coherence is a fundamental feature of quantum mechanics and an underlying requirement for most quantum information tasks. In the resource theory of coherence, incoherent states are diagonal with respect to a fixed orthonormal basis,…

Quantum Physics · Physics 2019-09-18 Felix Bischof , Hermann Kampermann , Dagmar Bruß

We report an experimental investigation of the role of measurement in quantum metrology when the states of the probes are mixed. In particular, we investigated optimized local measurements and general global projective measurements,…

Quantum Physics · Physics 2021-02-22 R. S. Piera , S. P. Walborn , G. H. Aguilar

The optimal measurement that discriminates nonorthogonal quantum states with fixed rates of inconclusive outcomes (FRIO) can be decomposed into an assisted separation of the inputs, yielding conclusive and inconclusive outputs, followed by…

Quantum Physics · Physics 2025-02-04 L. F. Melo , O. Jiménez , L. Neves

In this report, we present a framework for implementing an arbitrary $n$-outcome generalized quantum measurement (POVM) on an $m$-qubit register as a sequence of two-outcome measurements requiring only single ancillary qubit. Our procedure…

Quantum Physics · Physics 2024-07-16 Daniel Reitzner , Jan Bouda