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Related papers: Quantum discord for the general two-qubit case

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In this paper, we consider the global solutions to a generalized 2D Boussinesq equation \begin{align*} \left \{\begin{aligned} & \partial_{t} \omega + u\cdot \nabla \omega + \nu \Lambda^{\alpha} \omega = \theta_{x_{1}} , \quad \\ & u =…

Analysis of PDEs · Mathematics 2014-11-03 Junxiong Jia , Jigen Peng , Kexue Li

Two-level systems are one of the most important quantum systems and they form the basis of quantum computers. We briefly look at the traditional approach to two-level systems with an external driving field as well as those subjected to…

Quantum Physics · Physics 2016-09-14 Rajath Krishna R , N. S. Vidhyadhiraja

We study bipartite quantum discord as a manifestation of a multipartite entanglement structure in the tripartite purified system. In particular, we find that bipartite quantum discord necessarily manifests itself in the presence of both…

Quantum Physics · Physics 2013-07-29 Eric G. Brown , Eric J. Webster , Eduardo Martin-Martinez , Achim Kempf

We emphasize intertwining relations as a universal tool in constructing one-dimensional quasi-exactly solvable operators and offer their possible generalization to the multidimensional case. Considered examples include all quasi-exactly…

High Energy Physics - Theory · Physics 2007-05-23 Sergey Klishevich

We compare classical and quantum query complexities of total Boolean functions. It is known that for worst-case complexity, the gap between quantum and classical can be at most polynomial. We show that for average-case complexity under the…

Quantum Physics · Physics 2009-09-25 Andris Ambainis , Ronald de Wolf

We study the existence of cubic quotients of finite-dimensional quasi-normed spaces, that is, quotients well isomorphic to $\ell_{\infty}^k$ for some $k.$ We give two results of this nature. The first guarantees a proportional dimensional…

Functional Analysis · Mathematics 2007-05-23 N. J. Kalton , A. E. Litvak

As demonstrated by Boto et al. [Phys. Rev. Lett. 85, 2733 (2000)], quantum lithography offers an increase in resolution below the diffraction limit. Here, we generalize this procedure in order to create patterns in one and two dimensions.…

Quantum discord represents a correlation beyond classicality that could be useful for many quantum information tasks, and therefore is viewed as a valuable quantum resource. Theoretically, whether a bipartite quantum state has a non-zero…

Quantum Physics · Physics 2025-06-10 Rong Wang , Yao Yao , Zhen-Qiang Yin

We treat quantum counterparts of testing problems whose optimal tests are given by chi-square, t and F tests. These quantum counterparts are formulated as quantum hypothesis testing problems concerning quantum Gaussian states families, and…

Quantum Physics · Physics 2013-06-20 Wataru Kumagai , Masahito Hayashi

We study the existence of global positive solutions of the differential inequalities $$ - \operatorname{div} A (x, u, \nabla u) \ge f (u) \quad \mbox{in } {\mathbb R}^n, $$ where $n \ge 2$ and $A$ is a Carath\'eodory function such that $$…

Analysis of PDEs · Mathematics 2025-01-28 A. A. Kon'kov , A. E. Shishkov , M. D. Surnachev

We study the relation between quantum computational complexity and general relativity. The quantum computational complexity is proposed to be quantified by the shortest length of geodesic quantum curves. We examine the complexity/volume…

High Energy Physics - Theory · Physics 2018-03-14 Xian-Hui Ge , Bin Wang

The dipole-coupled two-level atoms(qubits) in a single-mode resonant cavity is studied by extended bosonic coherent states. The numerically exact solution is presented. For finite systems, the first-order quantum phase transitions occur at…

Quantum Physics · Physics 2015-05-19 Qing-Hu Chen , Tao Liu , Yu-Yu Zhang , Ke-Lin Wang

The effective description of loop quantum cosmology (LQC) has proved to be a convenient platform to study phenomenological implications of the quantum bounce that resolves the classical big-bang singularity. Originally, this description was…

General Relativity and Quantum Cosmology · Physics 2015-11-04 Abhay Ashtekar , Brajesh Gupt

Quantum machine learning explores the interplay between machine learning and quantum physics, which may lead to unprecedented perspectives for both fields. In fact, recent works have shown strong evidences that quantum computers could…

Quantum Physics · Physics 2021-11-08 Weiyuan Gong , Dong-Ling Deng

We show that the third-order difference equations proposed by Hirota, Kimura and Yahagi are generated by a pair of second-order difference equations. In some cases, the pair of the second-order equations are equivalent to the…

Exactly Solvable and Integrable Systems · Physics 2016-09-08 Junta Matsukidaira , Daisuke Takahashi

Deutsch's algorithm for two qubits (one control qubit plus one auxiliary qubit) is extended to two $d$-dimensional quantum systems or qudits for the case in which $d$ is equal to $2^n$, $n=1,2,...$ . This allows one to classify a certain…

Quantum Physics · Physics 2007-05-23 Jose L. Cereceda

A noncommutative algebra of the complex $q$-twistors and their differentials is considered on the basis of the quantum $GL_q (4)\times SL_q (2)$ group. Real and pseudoreal $q$-twistors are discussed too. We consider the quantum-group…

q-alg · Mathematics 2008-02-03 B. M. Zupnik

We found an universal local unitary (orthogonal) transformation which transforms any centrosymmetric (CS) density matrix \rho_{CS} into the X density matrix \rho_X: H\otimes H\rho_{CS}H\otimes H=\rho_X, where H is the Hadamard…

Quantum Physics · Physics 2013-04-16 M. A. Yurishchev

Quantum discord has been shown to be a resource for quantum advantage in addition to quantum entanglement. While many experiments have demonstrated classical analogies of entanglement, none have done so for discord. We present a…

The quantum circuit model is the most widely used model of quantum computation. It provides both a framework for formulating quantum algorithms and an architecture for the physical construction of quantum computers. However, several other…

Quantum Physics · Physics 2008-09-16 Stephen P. Jordan