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Related papers: N-qubit states as points on the Bloch sphere

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We describe designs for the realization of topological Majorana qubits in terms of proximitized topological insulator nanoribbons pierced by a uniform axial magnetic field. This platform holds promise for particularly robust Majorana bound…

Mesoscale and Nanoscale Physics · Physics 2017-04-18 Jan Manousakis , Alexander Altland , Dmitry Bagrets , Reinhold Egger , Yoichi Ando

We give a complete, hierarchic classification for arbitrary multi-qubit mixed states based on the separability properties of certain partitions. We introduce a family of N-qubit states to which any arbitrary state can be depolarized. This…

Quantum Physics · Physics 2009-10-31 W. Dür , J. I. Cirac

We discuss the problem of estimating a general (mixed) qubit state. We give the optimal guess that can be inferred from any given set of measurements. For collective measurements and for a large number $N$ of copies, we show that the error…

Quantum Physics · Physics 2009-11-10 E. Bagan , M. Baig , R. Munoz-Tapia , A. Rodriguez

Stabilizer states hold a special place in quantum information science due to their connection with quantum error correction and quantum circuit simulation. In the context of classical simulations of many-body physics, they are an example of…

Quantum Physics · Physics 2026-02-20 Tomislav Begušić , Garnet Kin-Lic Chan

We present a multipartite entanglement measure for $N$-qudit pure states, using the norm of the correlation tensor which occurs in the Bloch representation of the state. We compute this measure for important class of $N$-qutrit pure states,…

Quantum Physics · Physics 2010-01-01 Ali Saif M. Hassan , Pramod S. Joag

We investigate multiqubit permutation-symmetric states with maximal entropy of entanglement. Such states can be viewed as particular spin states, namely anticoherent spin states. Using the Majorana representation of spin states in terms of…

Quantum Physics · Physics 2015-12-01 D. Baguette , F. Damanet , O. Giraud , J. Martin

The geometrical description of Quantum Mechanics is reviewed and proposed as an alternative picture to the standard ones. The basic notions of observables, states, evolution and composition of systems are analised from this perspective, the…

Mathematical Physics · Physics 2019-03-26 Florio M. Ciaglia , Alberto Ibort , Giuseppe Marmo

Structured-Gaussian beams are shown to be fully and uniquely represented by a collection of points (or constellation) on the surface of the modal Majorana sphere, providing a complete generalization of the modal Poincar\'e sphere to…

Optics · Physics 2020-10-16 R. Gutiérrez-Cuevas , S. A. Wadood , A. N. Vamivakas , M. A. Alonso

A qubit chosen from equatorial or polar great circles on a Bloch sphere can be remotely prepared with an Einstain-Podolsky-Rosen (EPR) state shared and a cbit communication. We generalize this protocal into an arbitrary longitudinal qubit…

Quantum Physics · Physics 2007-05-23 Xinhua Peng , Xiwen Zhu , Maili Liu , Kelin Gao

Study of an N qubit mixed symmetric separable states is a long standing challenging problem as there exist no unique separability criterion. In this regard, we take up the N-qubit mixed symmetric separable states for a detailed study as…

Quantum Physics · Physics 2017-09-12 Suma SP , Swarnamala Sirsi , Subramanya Hegde , Karthik Bharath

We propose a novel method for image representation in quantum computers, which uses the two-dimensional (2-D) quantum states to locate each pixel in an image through row-location and column-location vectors for identifying each pixel…

Multimedia · Computer Science 2015-07-20 Madhur Srivastava , Subhayan R. Moulick , Prasanta K. Panigrahi

We study the separability of bipartite quantum systems in arbitrary dimensions based on the Bloch representation of density matrices. We present two separability criteria for quantum states in terms of the matrices $T_{\alpha\beta}(\rho)$…

Quantum Physics · Physics 2023-05-11 Xue-Na Zhu , Jing Wang , Gui Bao , Ming Li , Shu-Qian Shen , Shao-Ming Fei

We discuss and experimentally demonstrate a probabilistic Hadamard gate for coherent state qubits. The scheme is based on linear optical components, non-classical resources and the joint projective action of a photon counter and a homodyne…

Quantum Physics · Physics 2015-03-19 Anders Tipsmark , Ruifang Dong , Amine Laghaout , Petr Marek , Miroslav Jezek , Ulrik L. Andersen

Measurement-based quantum computation (MBQC) is a protocol for quantum computation that represents a model distinct from the circuit-based approach. MBQC has been proposed not only for qubits but also for qudits, continuous-variable (CV)…

Quantum Physics · Physics 2025-09-30 Genji Fujii

A Bloch sphere is the geometrical representation of an arbitrary two-dimensional Hilbert space. Possible classes of entanglement and separability for the pure and mixed states on the Bloch sphere were suggested by [M. Boyer, R. Liss, T.…

Quantum Physics · Physics 2020-03-31 Rotem Liss , Tal Mor , Roman Orus

We investigate the geometrical structure of multipartite states based on the construction of toric varieties. We show that the toric variety represents the space of general pure states and projective toric variety defines the space of…

Quantum Physics · Physics 2009-12-21 Hoshang Heydari

We study properties of representing and absolutely representing systems of subspaces in Banach spaces. We also present sufficient conditions for the system of subspaces to be a representing system of subspaces.

Functional Analysis · Mathematics 2012-01-17 Ivan Feshchenko

We investigate multipartite entanglement for composite quantum systems in a pure state. Using the generalized Bloch representation for n-qubit states, we express the condition that all k-qubit reductions of the whole system are maximally…

Quantum Physics · Physics 2013-02-01 Ludovic Arnaud , Nicolas J. Cerf

The aim of this paper is to introduce a new graphic representation of quantum states by means of a specific application: the analysis of two models of quantum copying machines. The graphic representation by diagrams of states offers a clear…

Quantum Physics · Physics 2007-05-23 Sara Felloni , Giuliano Strini

The quantum state of a system of qubits can be represented by a Wigner function on a discrete phase space, each axis of the phase space taking values in a finite field. Within this framework, we show that one can make sense of the notion of…

Quantum Physics · Physics 2007-05-23 William K. Wootters , Daniel M. Sussman