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Related papers: Disturbance by optimal discrimination

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We show that the quantum measurement known as the pretty good measurement can be used to identify an unknown quantum state picked from any set of $n$ mixed states that have pairwise fidelities upper-bounded by a constant below 1, given…

Quantum Physics · Physics 2019-11-11 Ashley Montanaro

Conventionally, unknown quantum states are characterized using quantum-state tomography based on strong or weak measurements carried out on an ensemble of identically prepared systems. By contrast, the use of protective measurements offers…

Quantum Physics · Physics 2016-01-25 Maximilian Schlosshauer

We consider optimal state discrimination in a general convex operational framework, so-called generalized probabilistic theories (GPTs), and present a general method of optimal discrimination by applying the complementarity problem from…

Quantum Physics · Physics 2017-07-11 Joonwoo Bae , D. -G. Kim , Leong-Chuan Kwek

Quantum mechanics predicts that measurements of incompatible observables carry a minimum uncertainty which is independent of technical deficiencies of the measurement apparatus or incomplete knowledge of the state of the system. Nothing yet…

Quantum Physics · Physics 2013-06-14 Davide Girolami , Tommaso Tufarelli , Gerardo Adesso

Any two-qubit state can be represented, geometrically, as an ellipsoid with a certain size and a center located within the Bloch sphere of one of the qubits. Points of this ellipsoid represent the post-measurement states when the other…

Quantum Physics · Physics 2018-10-18 Vahid Nassajpour , Seyed Javad Akhtarshenas

The quantum discrimination of two non-coherent states draws much attention recently. In this letter, we first consider the quantum discrimination of two noiseless displaced number states. Then we derive the Fock representation of noisy…

Quantum Physics · Physics 2020-12-10 Renzhi Yuan , Julian Cheng

Quantitative measures are introduced for the indistinguishability $U$ of two quantum states in a given measurement and the amount of interference $I$ observable in this measurement. It is shown that these measures obey an inequality $U\geq…

Quantum Physics · Physics 2007-05-23 Jos Uffink , Jan Hilgevoord

Quantum discord represents a correlation beyond classicality that could be useful for many quantum information tasks, and therefore is viewed as a valuable quantum resource. Theoretically, whether a bipartite quantum state has a non-zero…

Quantum Physics · Physics 2025-06-10 Rong Wang , Yao Yao , Zhen-Qiang Yin

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

We describe and realize an experimental procedure for assessing the incompatibility of two qubit measurements. The experiment consists in a state discrimination task where either measurement is used according to some partial intermediate…

It is shown that the dissonance, a quantum correlation which is equal to quantum discord for separable state, is required for assisted optimal state discrimination. We find that only one side discord is required in the optimal process of…

Quantum Physics · Physics 2012-02-24 Bo Li , Shao-Ming Fei , Zhi-Xi Wang , Heng Fan

In this contribution I review rigorous formulations of a variety of limitations of measurability in quantum mechanics. To this end I begin with a brief presentation of the conceptual tools of modern measurement theory. I will make precise…

Quantum Physics · Physics 2011-01-04 Paul Busch

One of the key issues in quantum discrimination problems is understanding the extent of the advantages in discrimination performance when using resource states compared to resourceless states. We show that in any resource theory of states,…

Quantum Physics · Physics 2025-09-16 Kenji Nakahira

The variety of multi-partite entangled states enables numerous applications in novel quantum information tasks. In order to compare the suitability of different states from a theoretical point of view classifications have been introduced.…

We investigate the discrimination of pure-mixed (quantum filtering) and mixed-mixed states and compare their optimal success probability with the one for discriminating other pairs of pure states superposed by the vectors included in the…

Quantum Physics · Physics 2021-12-24 Jin-Hua Zhang , Fu-Lin Zhang , Zhi-Xi Wang , Hui Yang , Shao-Ming Fei

We theoretically investigate schemes to discriminate between two nonorthogonal quantum states given multiple copies. We consider a number of state discrimination schemes as applied to nonorthogonal, mixed states of a qubit. In particular,…

Quantum Physics · Physics 2015-03-17 B. L. Higgins , A. C. Doherty , S. D. Bartlett , G. J. Pryde , H. M. Wiseman

We demonstrate that all good asymptotic entanglement measures are either identical or place a different ordering on the set of all quantum states.

Quantum Physics · Physics 2009-10-31 S. Virmani , M. B. Plenio

We study quantum metrology for unitary dynamics. Analytic solutions are given for both the optimal unitary state preparation starting from an arbitrary mixed state and the corresponding optimal measurement precision. This represents a…

Quantum Physics · Physics 2019-12-30 Lukas J. Fiderer , Julien M. E. Fraïsse , Daniel Braun

Quantum properties of the probes used to estimate a classical parameter can be used to attain accuracies that beat the standard quantum limit. When qubits are used to construct a quantum probe, it is known that initializing $n$ qubits in an…

Quantum Physics · Physics 2009-11-13 Anil Shaji , Carlton M. Caves

Recently there have been fruitful results on resource theories of quantum measurements. Here we investigate the number of measurement outcomes as a kind of resource. We cast the robustness of the resource as a semi-definite positive…

Quantum Physics · Physics 2022-09-28 Weixu Shi , Chaojing Tang