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Related papers: Qubit POVMs by destructive weak measurements

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In a recent paper, Buscemi and al. defined a notion of clean positive operator valued measures (POVMs). We here characterize which POVMs are clean in some class that we call quasi-qubit POVMs, namely POVMs whose elements are all rank-one or…

Quantum Physics · Physics 2015-06-26 Jonas Kahn

In contrast to a projective quantum measurement in which the system is projected onto an eigenstate of the measured operator, in a weak measurement the system is only weakly perturbed while only partial information on the measured…

Quantum Physics · Physics 2018-10-26 Maicol A. Ochoa , Wolfgang Belzig , Abraham Nitzan

Here we propose an implementation of all possible Positive Operator Value Measures (POVMs) of two-photon polarization states. POVMs are the most general class of quantum measurements. Our setup requires linear optics, Bell State…

Quantum Physics · Physics 2009-11-11 S. E. Ahnert , M. C. Payne

A large literature has grown up around the proposed use of 'weak measurements' (i.e., unsharp measurements followed by post-selection) to allegedly provide information about hidden ontological features of quantum systems. This paper…

Quantum Physics · Physics 2017-05-16 R. E. Kastner

Quantum parameter estimation holds significant promise for achieving high precision through the utilization of the most informative measurements. While various lower bounds have been developed to assess the best accuracy for estimates, they…

Quantum Physics · Physics 2024-07-19 Jianchao Zhang , Jun Suzuki

Measuring the polarisation of a single photon typically results in its destruction. We propose, demonstrate, and completely characterise a \emph{quantum non-demolition} (QND) scheme for realising such a measurement non-destructively. This…

Quantum Physics · Physics 2008-11-26 G. J. Pryde , J. L. O'Brien , A. G. White , S. D. Bartlett , T. C. Ralph

We perform generalized measurements of a qubit by realizing the qubit as a coin in a photonic quantum walk and subjecting the walker to projective measurements. Our experimental technique can be used to realize photonically any rank-1…

Quantum Physics · Physics 2015-08-11 Zhihao Bian , Jian Li , Hao Qin , Xiang Zhan , Rong Zhang , Barry C. Sanders , Peng Xue

Weak measurements of photon position can be used to obtain direct experimental evidence of the wavefunction of a photon between generation and ultimate detection. Significantly, these measurement results can also be understood as complex…

Quantum Physics · Physics 2014-06-11 Holger F. Hofmann

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

We study the decay of unstable states by formulating quantum tunneling as a time-of-arrival problem: we determine the detection probability for particles at a detector located a distance L from the tunneling region. For this purpose, we use…

Quantum Physics · Physics 2009-11-13 Charis Anastopoulos

Non-destructive weak measurements (WM) made on a quantum particle allow to extract information as the particle evolves from a prepared state to a finally detected state. The physical meaning of this information has been open to debate,…

Quantum Physics · Physics 2017-03-22 Q. Duprey , A. Matzkin

Quantum measurement not only can destroy coherence but also can create it. Here, we estimate the maximum amount of coherence, one can create under a complete non-selective measurement process. For our analysis, we consider projective as…

Quantum Physics · Physics 2022-03-14 Sanuja D. Mohanty , Gautam Sharma , Sk Sazim , Biswajit Pradhan , Arun K. Pati

Weak measurement has been shown to play important roles in the investigation of both fundamental and practical problems. Anomalous weak values are generally believed to be observed only when post-selection is performed, i.e, only a…

Quantum Physics · Physics 2019-11-26 Mu Yang , Qiang Li , Zheng-Hao Liu , Ze-Yan Hao , Chang-Liang Ren , Jin-Shi Xu , Chuan-Feng Li , Guang-Can Guo

Determining the conditions under which positive operator-valued measures (POVMs), the most general class of quantum measurements, outperform projective measurements remains a challenging and largely unresolved problem. Of particular…

We explore the use of weak quantum measurements for single-qubit quantum state tomography processes. Weak measurements are those where the coupling between the qubit and the measurement apparatus is weak; this results in the quantum state…

Quantum Physics · Physics 2017-11-15 Shoumik Chowdhury

Minimal informationally complete positive operator-valued measures (MIC-POVMs) are special kinds of measurement in quantum theory in which the statistics of their $d^2$-outcomes are enough to reconstruct any $d$-dimensional quantum state.…

Considering ultracold atoms traversing a high-Q Fabry-Perot cavity, we theoretically demonstrate a quantum nondemolition measurement of the photon number. This fully quantum mechanical approach may be understood utilizing concepts as…

Quantum Physics · Physics 2009-11-13 Jonas Larson , Mahmoud Abdel-Aty

The article undertakes the problem of pure state estimation from projective measurements based on photon counting. Two generic frames for qubit tomography are considered -- one composed of the elements of the SIC-POVM and the other defined…

Quantum Physics · Physics 2021-03-02 Artur Czerwinski

In a previous paper we have presented a general scheme for the implementation of symmetric generalized measurements (POVMs) on a quantum computer. This scheme is based on representation theory of groups and methods to decompose matrices…

Quantum Physics · Physics 2015-06-26 Dominik Janzing , Thomas Decker

Quantum measurements can be generalized to include complex quantities. It is possible to relate the quantum weak values of projection operators to the third order Bargmann invariants. The argument of the weak value becomes, up to a sign,…

Quantum Physics · Physics 2021-09-22 Z. Gedik