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Related papers: Discrete phase-space structure of $n$-qubit mutual…

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Mutually unbiased bases (MUBs), which are such that the inner product between two vectors in different orthogonal bases is constant equal to the inverse $1/\sqrt{d}$, with $d$ the dimension of the finite Hilbert space, are becoming more and…

Quantum Physics · Physics 2009-11-11 Michel Planat , Haret Rosu

Mutually unbiased bases (MUBs) play a key role in many protocols in quantum science, such as quantum key distribution. However, defining MUBs for arbitrary high-dimensional systems is theoretically difficult, and measurements in such bases…

Quantum Physics · Physics 2013-04-03 D. Giovannini , J. Romero , J. Leach , A. Dudley , A. Forbes , M. J. Padgett

Mutually unbiased bases that can be cyclically generated by a single unitary operator are of special interest, since they can be readily implemented in practice. We show that, for a system of qubits, finding such a generator can be cast as…

Quantum Physics · Physics 2015-06-19 Ulrich Seyfarth , Luis L. Sanchez-Soto , Gerd Leuchs

We study the connection between mutually unbiased bases and mutually orthogonal extraordinary supersquares, a wider class of squares which does not contain only the Latin squares. We show that there are four types of complete sets of…

Quantum Physics · Physics 2014-04-24 Iulia Ghiu , Cristian Ghiu

We present a detailed computational and algebraic study of Mutually Unbiased Bases (MUBs) in finite-dimensional Hilbert spaces, with a particular focus on dimensions 2, 3, 4, and the challenging case of 6. Starting from the Hadamard-phase…

Quantum Physics · Physics 2026-04-03 Jean-Christophe Pain

In contrast to abstract statistical analyses in the literature, we present a concrete physical diagrammatic model of entanglement characterization and measure with its underlying discrete phase-space physics. This paper serves as a…

Quantum Physics · Physics 2023-05-30 Felix A. Buot

In quantum mechanics some properties are maximally incompatible, such as the position and momentum of a particle or the vertical and horizontal projections of a 2-level spin. Given any definite state of one property the other property is…

Quantum Physics · Physics 2009-11-13 A. J. Skinner , V. A. Newell , R. Sanchez

A new approach extending the concept of geometric phases to adiabatic open quantum systems described by density matrices (mixed states) is proposed. This new approach is based on an analogy between open quantum systems and dissipative…

Mathematical Physics · Physics 2011-08-31 David Viennot , Jose Lages

We study the noncommutative geometrical structures of quantum entangled states. We show that the space of a pure entangled state is a noncommutative space. In particular we show that by rewritten the conifold or the Segre variety we can get…

Quantum Physics · Physics 2015-05-19 Hoshang Heydari

Quantum theory of field (extended) objects without a priori space-time geometry has been represented. Intrinsic coordinates in the tangent fibre bundle over complex projective Hilbert state space $CP(N-1)$ are used instead of space-time…

General Physics · Physics 2007-05-23 Peter Leifer

We construct an informationally complete set of mutually unbiased - like bases for N ququarts. These bases are used in an explicit tomographic protocol which performance is analyzed by estimating quadratic errors and compared to other…

Quantum Physics · Physics 2021-08-10 Juan Díaz-Guevara , Isabel Sainz , Andrei B. Klimov

We analyze the operation of quantum gates for neutral atoms with qubits that are delocalized in space, i.e., the computational basis states are defined by the presence of a neutral atom in the ground state of one out of two trapping…

Quantum Physics · Physics 2009-11-07 J. Mompart , K. Eckert , W. Ertmer , G. Birkl , M. Lewenstein

Using measures of entanglement such as negativity and tangles we provide a detailed analysis of entanglement structures in pure states of non-interacting qubits. The motivation for this exercise primarily comes from holographic…

High Energy Physics - Theory · Physics 2015-08-28 Mukund Rangamani , Massimiliano Rota

We generalize the concept of mutually unbiased bases (MUB) to measurements which are not necessarily described by rank one projectors. As such, these measurements can be a useful tool to study the long standing problem of the existence of…

Quantum Physics · Physics 2015-06-18 Amir Kalev , Gilad Gour

We study phase structures of quantum field theories in fuzzy geometries. Several examples of fuzzy geometries as well as QFT's on such geometries are considered. They are fuzzy spheres and beyond as well as noncommutative deformations of…

High Energy Physics - Theory · Physics 2012-04-30 T R Govindarajan , S. Digal , K. S. Gupta , X. Martin

We investigate the interplay between mutual unbiasedness and product bases for multiple qudits of possibly different dimensions. A product state of such a system is shown to be mutually unbiased to a product basis only if each of its…

Quantum Physics · Physics 2016-03-18 Daniel McNulty , Bogdan Pammer , Stefan Weigert

We experimentally generate and tomographically characterize a mixed, genuinely non-Gaussian bipartite continuous-variable entangled state. By testing entanglement in 2$\times$2-dimensional two-qubit subspaces, entangled qubits are localized…

Quantum Physics · Physics 2015-03-17 T. Kiesel , W. Vogel , B. Hage , R. Schnabel

Motivated by recent experiments, we study the dynamics of a qubit quadratically coupled to its detector, a damped harmonic oscillator. We use a complex-environment approach, explicitly describing the dynamics of the qubit and the oscillator…

Mesoscale and Nanoscale Physics · Physics 2007-09-17 I. Serban , E. Solano , F. K. Wilhelm

Maximal sets of mutually unbiased bases are useful throughout quantum physics, both in a foundational context and for applications. To date, it remains unknown if complete sets of mutually unbiased bases exist in Hilbert spaces of…

Quantum Physics · Physics 2026-04-09 Daniel McNulty , Stefan Weigert

Nonadiabatic geometric quantum computation in decoherence-free subspaces has received increasing attention due to the merits of its high-speed implementation and robustness against both control errors and decoherence. However, all the…

Quantum Physics · Physics 2017-01-04 P. Z. Zhao , G. F. Xu , D. M. Tong