Results 21 to 30 of about 1,857,430 (354)
Entanglement Structure of the Adjoint Representation of the Unitary Group and Tomography of Quantum States [PDF]
Journal of Russian Laser Research, 2003 The density matrix of composite spin system is discussed in relation to the adjoint representation of unitary group $U(n)$. The entanglement structure is introduced as an additional ingredient to the description of the linear space carrying the adjoint ...
Vladimir I. Man'ko, G Marmo
exaly +2 more sources
On MMSE and MAP Denoising Under Sparse Representation Modeling Over a Unitary Dictionary [PDF]
IEEE Transactions on Signal Processing, 2010 Among the many ways to model signals, a recent approach that draws considerable attention is sparse representation modeling. In this model, the signal is assumed to be generated as a random linear combination of a few atoms from a prespecified dictionary.
Javier Turek, I. Yavneh, Michael Elad
semanticscholar +3 more sources
Unitary (semi)causal quantum-circuit representation of black hole evaporation [PDF]
European Physical Journal C: Particles and FieldsA general structure of unitary evolution (evaporation) of the black hole, respecting causality imposed by the event horizon (semicausality), has been derived and presented in the language of quantum circuits.
Bogusław Broda
doaj +2 more sources
The Explicit Form of the Unitary Representation of the Poincaré Group for Vector-Valued Wave Functions (Massive and Massless), with Applications to Photon Localization and Position Operators [PDF]
MathematicsWe geometrically derive the explicit form of the unitary representation of the Poincaré group for vector-valued wave functions and use it to apply speed-of-light boosts to a simple polarization basis to end up with a Hawton–Baylis photon position ...
Arkadiusz Jadczyk
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On families of twisted power partial isometries
Karpatsʹkì Matematičnì Publìkacìï, 2022 We consider families of power partial isometries satisfying twisted commutation relations with deformation parameters $\lambda_{ij}\in\mathbb C$, $|\lambda_{ij}|=1$.
V.L. Ostrovskyi +2 more
doaj +1 more source
Detecting mixed-unitary quantum channels is NP-hard [PDF]
Quantum, 2020 A quantum channel is said to be a $\textit{mixed-unitary}$ channel if it can be expressed as a convex combination of unitary channels. We prove that, given the Choi representation of a quantum channel $\Phi$, it is NP-hard with respect to polynomial-time
Colin Do-Yan Lee, John Watrous
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Transfer of Unitary Representations [PDF]
Asian Journal of Mathematics, 2004 In the present paper, the authors explain and give applications of the notion of transfer between real forms of a semi-simple Lie group \(G^{\mathbb C}\) over \(\mathbb C\), which first appeared in [\textit{N. R. Wallach}, Contemp. Math. 177, 181--216 (1994; Zbl 0833.22021)]. The main idea is that some representation of a real form of \(G^{\mathbb C}\)
Wallach, Nolan R., Zhu, Chen-Bo
openaire +2 more sources
Representation Matching For Remote Quantum Computing
PRX Quantum, 2021 Many quantum computational tasks have inherent symmetries, suggesting a path to enhancing their efficiency and performance. Exploiting this observation, we propose representation matching, a generic probabilistic protocol for reducing the cost of quantum
Yuxiang Yang, Masahito Hayashi
doaj +1 more source
Local unitary representation of braids and N-qubit entanglements [PDF]
Quantum Information Processing, 2017 In this paper, by utilizing the idea of stabilizer codes, we give some relationships between one local unitary representation of braid group in N-qubit tensor space and the corresponding entanglement properties of the N-qubit pure state $$|\varPsi ...
Li-Wei Yu
semanticscholar +1 more source
Algebras Generated by Finite Subgroups of Unitary Groups
Journal of Harbin University of Science and Technology, 2021 Group representation theory is one of the most powerful tools to study groups. The unitary group is an important research branch of group theories. We study a class of algebraic structures generated by unitary groups，and we prove that Alg( H) is a von ...
LUO Lai-zhen, LI Xing-hua, TAO Yuan-hong
doaj +1 more source