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Related papers: Concurrence of Stochastic 1-Qubit Maps

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In this work, we study the numerical optimization of nearest-neighbor concurrence of bipartite one and two dimensional lattices, as well as non bipartite two dimensional lattices. These systems are described in the framework of a…

Quantum Physics · Physics 2015-05-13 J. C. Navarro-Munoz , R. Lopez-Sandoval , M. E. Garcia

Let $T$ be a competitive map on a rectangular region $\mathcal{R}\subset \mathbb{R}^2$, and assume $T$ is $C^1$ in a neighborhood of a fixed point $\bar{\rm x}\in \mathcal{R}$. The main results of this paper give conditions on $T$ that…

Dynamical Systems · Mathematics 2015-05-13 Mustafa Kulenovic , Orlando Merino

Let $T$ be a $C^{1}$ competitive map on a rectangular region $R\subset \mathbb{R}^{2}$. The main results of this paper give conditions which guarantee the existence of an invariant curve $C$, which is the graph of a continuous increasing…

Dynamical Systems · Mathematics 2012-03-06 Gabriel Lugo , Frank J. Palladino

Geometric relations between separable and entangled two-qubit and two-qutrit quantum information states are studied. To characterize entanglement of two qubit states, we establish a relation between reduced density matrix and the…

Quantum Physics · Physics 2022-07-11 Oktay K Pashaev

We offer a systematic account of decomposition of quantum systems into parts. Different decompositions (structures) are mutually linked via the proper linear canonical transformations. Different kinds of structures, as well as their…

Quantum Physics · Physics 2014-06-03 Jasmina Jeknic-Dugic , Momir Arsenijevic , Miroljub Dugic

The stabilizing properties of one-error correcting jump codes are explored under realistic non-ideal conditions. For this purpose the quantum algorithm of the tent-map is decomposed into a universal set of Hamiltonian quantum gates which…

Quantum Physics · Physics 2007-05-23 Oliver Kern , Gernot Alber

For the online transportation problem with $m$ server sites, it has long been known that the competitive ratio of any deterministic algorithm is at least $2m-1$. Kalyanasundaram and Pruhs conjectured in 1998 that a deterministic…

Data Structures and Algorithms · Computer Science 2025-04-24 Tsubasa Harada , Toshiya Itoh

We present a new approach to the analysis of entanglement in smooth bipartite continuous-variable states. One or both parties perform projective filterings via preliminary measurements to determine whether the system is located in some…

Quantum Physics · Physics 2009-11-13 H. -C. Lin , A. J. Fisher

In this paper we introduce a new technique to analyze families of rankings focused on the study of structural properties of a new type of graphs. Given a finite number of elements and a family of rankings of those elements, we say that two…

Combinatorics · Mathematics 2014-03-26 Regino Criado , Esther Garcia , Francisco Pedroche , Miguel Romance

Concurrence, as one of entanglement measures, is a useful tool to characterize quantum entanglement in various quantum systems. However, the computation of the concurrence involves difficult optimizations and only for the case of two qubits…

Quantum Physics · Physics 2017-03-06 Xianfei Qi , Ting Gao , Femgli Yan

Quantum entanglement is a crucial resource in quantum information processing, advancing quantum technologies. The greater the uncertainty in subsystems' pure states, the stronger the quantum entanglement between them. From the dual form of…

Quantum Physics · Physics 2026-01-01 Dong-Ping Xuan , Zhong-Xi Shen , Wen Zhou , Zhi-Xi Wang , Shao-Ming Fei

We obtain a new inequality for arbitrary Hermitian matrices. We describe particular linear maps called the matrix portrait of arbitrary NxN matrices. The maps are obtained as analogs of partial tracing of density matrices of multipartite…

Quantum Physics · Physics 2014-04-15 Margarita A. Man'ko , Vladimir I. Man'ko

By focusing on the X-matrix part of a density matrix of two qubits we provide an algebraic lower bound for the concurrence. The lower bound is generalized for cases beyond two qubits and can serve as a sufficient condition for…

Quantum Physics · Physics 2012-04-19 S. M. Hashemi rafsanjani , S. Agarwal

We study market making in aggregator-routed RFQ markets where platform routing depends on slowly varying dealer performance scores. We propose a two-tier stochastic control model that separates RFQ-level price competition from a macro…

Risk Management · Quantitative Finance 2026-03-12 Alexander Barzykin

Given two hyperbolic surfaces and a homotopy class of maps between them, Thurston proved that there always exists a representative minimizing the Lipschitz constant. While not unique, these minimizers are rigid along a geodesic lamination.…

Geometric Topology · Mathematics 2025-10-24 Aaron Calderon , Jing Tao

We investigate linear maps between matrix algebras that remain positive under tensor powers, i.e., under tensoring with $n$ copies of themselves. Completely positive and completely co-positive maps are trivial examples of this kind. We show…

Quantum Physics · Physics 2015-12-22 Alexander Müller-Hermes , David Reeb , Michael M. Wolf

We show that approximating the trace norm contraction coefficient of a quantum channel within a constant factor is NP-hard. Equivalently, this shows that determining the optimal success probability for encoding a bit in a quantum system…

Quantum Physics · Physics 2025-09-23 Idris Delsol , Omar Fawzi , Jan Kochanowski , Akshay Ramachandran

We formalise decompression planning as an optimal control problem with gas feasibility windows (ppO$_2$, END), affine ceilings, and convex penalties in normalised oversaturation. The depth trajectory is constrained to be a monotone ascent,…

Optimization and Control · Mathematics 2026-05-19 Benjamin Marsh

We investigate a two-qubit system to understand the relationship between concurrence and mutual information, where the former determines the amount of quantum entanglement, whereas the latter is its classical residue after performing local…

Quantum Physics · Physics 2022-10-05 Yong Kwon , Seung Ki Baek , Jaegon Um

We show that every automorphism of a thick twin building interchanging the halves of the building maps some residue to an opposite one. Furthermore we show that no automorphism of a locally finite 2-spherical twin building of rank at least…

Combinatorics · Mathematics 2012-03-29 Alice Devillers , James Parkinson , Hendrik Van Maldeghem