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Related papers: Ancilla Approximable Quantum State Transformations

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The problem of unambiguously distinguishing among nonorthogonal but linearly independent quantum states can be solved by mapping the set of nonorthogonal quantum states onto a set of orthogonal ones, which can then be distinguished without…

Quantum Physics · Physics 2009-11-06 Yuqing Sun , Mark Hillery , Janos Bergou

Estimation of quantum states and measurements is crucial for the implementation of quantum information protocols. The standard method for each is quantum tomography. However, quantum tomography suffers from systematic errors caused by…

Quantum Physics · Physics 2018-10-19 Adam C. Keith , Charles H. Baldwin , Scott Glancy , E. Knill

We investigate the extent to which we can establish whether or not two quantum systems have been prepared in the same state. We investigate the possibility of universal unambiguous state comparison. We show that it is impossible to…

Quantum Physics · Physics 2009-11-07 Stephen M. Barnett , Anthony Chefles , Igor Jex

We introduce a fast and accurate heuristic for adaptive tomography that addresses many of the limitations of prior methods. Previous approaches were either too computationally intensive or tailored to handle special cases such as single…

Quantum Physics · Physics 2017-11-16 Christopher Granade , Christopher Ferrie , Steven T. Flammia

Quantum entanglement is the quantum information processing resource. Thus it is of importance to understand how much of entanglement particular quantum states have, and what kinds of laws entanglement and also transformation between…

Quantum Physics · Physics 2007-05-23 Toshiyuki Shimono

We survey various recent results that rigorously study the complexity of learning quantum states. These include progress on quantum tomography, learning physical quantum states, alternate learning models to tomography and learning classical…

Quantum Physics · Physics 2023-06-01 Anurag Anshu , Srinivasan Arunachalam

It is nowadays accepted that truly quantum correlations can exist even in the absence of entanglement. For the case of symmetric states, a physically trivial unitary transformation can alter a quantum state from entangled to separable and…

Quantum Physics · Physics 2022-02-24 Aaron Z. Goldberg , Markus Grassl , Gerd Leuchs , Luis L. Sánchez-Soto

Extracting information from quantum devices has long been a crucial problem in the field of quantum mechanics. By performing elaborate measurements, quantum state tomography, an important and fundamental tool in quantum science and…

Quantum Physics · Physics 2022-06-24 Yu Wang , Keren Li

We show how quantum dynamics (a unitary transformation) can be captured in the state of a quantum system, in such a way that the system can be used to perform, at a later time, the stored transformation almost perfectly on some other…

Quantum Physics · Physics 2007-05-23 G. Vidal , J. I. Cirac

We investigate probabilistic transformations of quantum states from a `source' set to a `target' set of states. Such transforms have many applications. They can be used for tasks which include state-dependent cloning or quantum state…

Quantum Physics · Physics 2015-06-05 Vedran Dunjko , Erika Andersson

We describe algorithms to obtain an approximate classical description of a $d$-dimensional quantum state when given access to a unitary (and its inverse) that prepares it. For pure states we characterize the query complexity for…

Quantum Physics · Physics 2022-07-19 Joran van Apeldoorn , Arjan Cornelissen , András Gilyén , Giacomo Nannicini

A careful study of the classical/quantum connection with the aid of coherent states offers new insights into various technical problems. This analysis includes both canonical as well as closely related affine quantization procedures. The…

High Energy Physics - Theory · Physics 2015-06-12 John R. Klauder

We present the first complete optimization of quantum tomography, for states, POVMs, and various classes of transformations, for arbitrary prior ensemble and arbitrary representation, giving corresponding feasible experimental schemes.

Quantum Physics · Physics 2009-11-13 A. Bisio , G. Chiribella , G. M. D'Ariano , S. Facchini , P. Perinotti

We discuss the "partial" quantum cloning of the pure two-partite states, when the "part" of initial state related to the one qubit is copied only. The same approach gives the possibility to design the quantum copying machine for the mixed…

Quantum Physics · Physics 2007-11-20 A. Ya. Kazakov

Using the necessary and sufficient conditions, minimum error discrimination among two sets of similarity transformed equiprobable quantum qudit states is investigated. In the case that the unitary operators are generating sets of two…

Quantum Physics · Physics 2016-11-25 M. A. Jafarizadeh , Y. Mazhari Khiavi , Y. Akbari Kourbolagh

We consider realistic measurement systems, where measurements are accompanied by decoherence processes. The aim of this work is the construction of methods and algorithms for precise quantum measurements with fidelity close to the…

Quantum Physics · Physics 2017-01-10 Yu. I. Bogdanov , B. I. Bantysh , N. A. Bogdanova , A. B. Kvasnyy , V. F. Lukichev

We construct a quantum algorithm that performs function-dependent phase transform and requires no initialization of an ancillary register. The algorithm recovers the initial state of an ancillary register regardless of whether its state is…

Quantum Physics · Physics 2007-05-23 Dong Pyo Chi , Jinsoo Kim , Soojoon Lee

The principle of teleportation can be used to perform a quantum computation even before its quantum input is defined. The basic idea is to perform the quantum computation at some earlier time with qubits which are part of an entangled…

Quantum Physics · Physics 2009-11-07 Caslav Brukner , Jian-Wei Pan , Christoph Simon , Gregor Weihs , Anton Zeilinger

A quantum gate is realized by specific unitary transformations operating on states representing qubits. Considering a quantum system employed as an element in a quantum computing scheme, the task is therefore to enforce the pre-specified…

Quantum Physics · Physics 2007-05-23 Jose P. Palao , Ronnie Kosloff

We introduce a versatile method for preparing a quantum state whose amplitudes are given by some known function. Unlike existing approaches, our method does not require handcrafted reversible arithmetic circuits, or quantum table reads, to…

Quantum Physics · Physics 2025-07-10 Sam McArdle , András Gilyén , Mario Berta