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An incoherent control scheme for state control of locally controllable quantum systems is proposed. This scheme includes three steps: (1) amplitude amplification of the initial state by a suitable unitary transformation, (2) projective…

Quantum Physics · Physics 2008-10-22 Daoyi Dong , Chenbin Zhang , Herschel Rabitz , Alexander Pechen , Tzyh-Jong Tarn

In the scenario of the probe-ancilla interaction, we propose a quantum metrology protocol by the unconditional measurement on the ancillary qubit after an optimized period of joint evolution from product state. Its key element is the…

Quantum Physics · Physics 2025-09-12 Peng Chen , Jun Jing

Quantum tomography is an important tool for obtaining information about the quantum state from experimental data. In this study, we conduct a comparative analysis of various quantum tomography protocols, including protocols based on highly…

Quantum Physics · Physics 2022-01-11 Yu. I. Bogdanov , B. I. Bantysh , N. A. Bogdanova , K. B. Koksharov , V. F. Lukichev

In this paper, we derive optimized measurement-free protocols for quantum error correction and the implementation of a universal gate set optimized for an error model that is noise biased . The noise bias is adapted for neutral atom…

One of the most promising applications of quantum computing is the processing of graphical data like images. Here, we investigate the possibility of realizing a quantum pattern recognition protocol based on swap test, and use the IBMQ noisy…

Quantum Physics · Physics 2023-04-05 Sreetama Das , Jingfu Zhang , Stefano Martina , Dieter Suter , Filippo Caruso

We propose and analyze a versatile and efficient multiparameter quantum sensing protocol, which simultaneously estimates many non-commuting and time-dependent signals that are coherently or incoherently coupled to sensing particles. Even in…

Quantum Physics · Physics 2026-02-02 Wenjie Gong , Bingtian Ye , Daniel Mark , Soonwon Choi

Many quantum algorithms rely on the measurement of complex quantum amplitudes. Standard approaches to obtain the phase information, such as the Hadamard test, give rise to large overheads due to the need for global controlled-unitary…

Quantum Physics · Physics 2024-05-29 Yilun Yang , Arthur Christianen , Mari Carmen Bañuls , Dominik S. Wild , J. Ignacio Cirac

In quantum computation, amplitude estimation is a fundamental subroutine that is utilized in various quantum algorithms. A general important task of such estimation problems is to characterize the estimation lower bound, which is referred…

Quantum Physics · Physics 2025-07-10 Kohei Oshio , Yohichi Suzuki , Kaito Wada , Keigo Hisanaga , Shumpei Uno , Naoki Yamamoto

It is well known that a quantum correlated probe can yield better precision in estimating an unknown parameter than classically possible. However, how such a quantum probe should be measured remains somewhat elusive. We examine the role of…

Quantum Physics · Physics 2015-02-20 K. Micadei , D. A. Rowlands , F. A. Pollock , L. C. Céleri , R. M. Serra , K. Modi

We develop an efficient algorithm for determining optimal adaptive quantum estimation protocols with arbitrary quantum control operations between subsequent uses of a probed channel. We introduce a tensor network representation of an…

We discuss a scheme in which sequential state-discrimination measurements are performed on qudits to determine the quantum state in which they were initially prepared. The qudits belong to a set of nonorthogonal quantum states and hence…

Quantum Physics · Physics 2017-10-17 Mark Hillery , Jihane Mimih

Quantum computation offers a promising new kind of information processing, where the non-classical features of quantum mechanics can be harnessed and exploited. A number of models of quantum computation exist, including the now well-studied…

Quantum Physics · Physics 2011-08-03 H. J. Briegel , D. E. Browne , W. Dür , R. Raussendorf , M. Van den Nest

The existence of incompatible measurements is a fundamental phenomenon having no explanation in classical physics. Intuitively, one considers given measurements to be incompatible within a framework of a physical theory, if their…

Quantum Physics · Physics 2015-08-27 Teiko Heinosaari , Jukka Kiukas , Daniel Reitzner

Random access code (RAC) communication protocol particularly useful when the communication between parties is restricted. In this work we built upon works that have previously proven quantum random access code (QRAC), in the absence of…

Quantum Physics · Physics 2024-02-07 Breno Marques , Rafael A. da Silva

The quantum measurement process by a single-electron transistor or a quantum point contact coupled to a quantum bit is studied. We find a unified description of the statistics of the monitored quantity, the current, in the regime of strong…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Yuriy Makhlin , Gerd Schoen , Alexander Shnirman

Quantum tomography is the main method used to assess the quality of quantum information processing devices, but its complexity presents a major obstacle for the characterization of even moderately large systems. The number of experimental…

Quantum Physics · Physics 2015-03-19 Marcus P. da Silva , Olivier Landon-Cardinal , David Poulin

Efficient methods for characterizing the performance of quantum measurements are important in the experimental quantum sciences. Ideally, one requires both a physically relevant distinguishability measure between measurement operations and…

Quantum Physics · Physics 2015-06-12 Easwar Magesan , Paola Cappellaro

The measurement and characterization of noise is a flourishing area of research in mesoscopic physics. In this work, we propose interaction-free measurements as a noise-detection technique, exploring two conceptually different schemes: the…

Quantum Physics · Physics 2024-09-06 John J. McCord , Shruti Dogra , Gheorghe Sorin Paraoanu

Measurement incompatibility describes two or more quantum measurements whose expected joint outcome on a given system cannot be defined. This purely non-classical phenomenon provides a necessary ingredient in many quantum information tasks…

Quantum Physics · Physics 2020-04-01 Francesco Buscemi , Eric Chitambar , Wenbin Zhou

Correctly characterizing state preparation and measurement (SPAM) processes is a necessary step towards building reliable quantum processing units (QPUs). In this work, we discuss the subtleties behind separately measuring SPAM errors. We…

Quantum Physics · Physics 2021-11-03 Junan Lin , Joel J. Wallman , Ian Hincks , Raymond Laflamme
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