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The geometrical arrangement of a set of quantum states can be completely characterized using relational information only. This information is encoded in the pairwise state overlaps, as well as in Bargmann invariants of higher degree written…

Quantum Physics · Physics 2021-09-22 Michał Oszmaniec , Daniel J. Brod , Ernesto F. Galvão

Successive pairs of pseudo-random numbers generated by standard linear congruential transformations display ordered patterns of parallel lines. We study the ``ordered'' and ``chaotic'' distribution of such pairs by solving the eigenvalue…

chao-dyn · Physics 2015-06-24 Antonio Bonelli , Stefano Ruffo

Eigenvalues of a density matrix characterize well the quantum state's properties, such as coherence and entanglement. We propose a simple method to determine all the eigenvalues of an unknown density matrix of a finite-dimensional system in…

Quantum Physics · Physics 2014-01-24 Tohru Tanaka , Yukihiro Ota , Mitsunori Kanazawa , Gen Kimura , Hiromichi Nakazato , Franco Nori

We apply the operation of random independent thinning on the eigenvalues of $n\times n$ Haar distributed unitary random matrices. We study gap probabilities for the thinned eigenvalues, and we study the statistics of the eigenvalues of…

Mathematical Physics · Physics 2017-08-14 Christophe Charlier , Tom Claeys

The study of entanglement properties of multi-qubit states that are invariant under permutations of qubits is motivated by potential applications in quantum computing, quantum communication, and quantum metrology. In this work, we…

Quantum Physics · Physics 2022-04-01 David W. Lyons , Jesse R. Arnold , Ashley F. Swogger

As quantum technologies mature, the development of tools for benchmarking their ability to prepare and manipulate complex quantum states becomes increasingly necessary. A key concept, the state overlap between two quantum states, offers a…

Quantum Physics · Physics 2021-12-23 Leonardo Guerini , Roeland Wiersema , Juan Felipe Carrasquilla , Leandro Aolita

In this article we propose a method to estimate with high accuracy pure quantum states of a single qudit. Our method is based on the minimization of the squared error between the complex probability amplitudes of the unknown state and its…

Quantum Physics · Physics 2021-07-14 A. Rojas , L. Pereira , S. Niklitschek , A. Delgado

Entanglement plays an important role in quantum communication, algorithms, and error correction. Schmidt coefficients are correlated to the eigenvalues of the reduced density matrix. These eigenvalues are used in Von Neumann entropy to…

Quantum Physics · Physics 2014-09-25 Anmer Daskin , Ananth Grama , Sabre Kais

The ability to quantify distinctness of a cluster structure is fundamental for certain simulation studies, in particular for those comparing performance of different classification algorithms. The intrinsic integral measure based on the…

Statistics Theory · Mathematics 2014-07-29 Ewa Nowakowska , Jacek Koronacki , Stan Lipovetsky

Quantum theory is traditionally formulated using complex numbers. This imaginarity of quantum theory has been quantified as a resource with applications in discrimination tasks, pseudorandomness generation, and quantum metrology. Here we…

Quantum Physics · Physics 2024-11-15 Carlos Fernandes , Rafael Wagner , Leonardo Novo , Ernesto F. Galvão

A finite dimensional quantum system for which the quantum chaos conjecture applies has eigenstates, which show the same statistical properties than the column vectors of random orthogonal or unitary matrices. Here, we consider the different…

Mathematical Physics · Physics 2017-10-05 L. Alonso , T. Gorin

Recent developments in mathematics have provided powerful tools for comparing the eigenvalues of matrices related to each other via a moment map. In this paper we survey some of the more concrete aspects of the approach with a particular…

Quantum Physics · Physics 2007-05-23 Sumit Daftuar , Patrick Hayden

We consider the problem of determining the mixed quantum state of a large but finite number of identically prepared quantum systems from data obtained in a sequence of ideal (von Neumann) measurements, each performed on an individual copy…

Quantum Physics · Physics 2009-11-10 Franz Embacher , Heide Narnhofer

Estimating the eigenvalues of a unitary transformation U by standard phase estimation requires the implementation of controlled-U-gates which are not available if U is only given as a black box. We show that a simple trick allows to measure…

Quantum Physics · Physics 2007-05-23 Dominik Janzing , Thomas Beth

The degree of entanglement of random pure states in bipartite quantum systems can be estimated from the distribution of the extreme Schmidt eigenvalues. For a bipartition of size M\geq N, these are distributed according to a…

Mathematical Physics · Physics 2011-06-07 Gernot Akemann , Pierpaolo Vivo

Quantum machine learning seeks a computational advantage in data processing by evaluating functions of quantum states, such as their similarity, that can be classically intractable to compute. For quantum advantage to be possible, however,…

Standard quantum phase estimation (QPE) has often been regarded as unsuitable for simultaneous detection of all eigenvalues, because it requires initial states with sufficient overlap with the target eigenstates. In this paper, we show that…

Quantum Physics · Physics 2026-04-02 Yuki Izumi , Hitoshi Kawahara

Perhaps the quantum state represents information about reality, and not reality directly. Wave function collapse is then possibly no more mysterious than a Bayesian update of a probability distribution given new data. We consider models for…

Quantum Physics · Physics 2012-11-20 Peter G. Lewis , David Jennings , Jonathan Barrett , Terry Rudolph

We investigate the equivalence of bipartite quantum mixed states under local unitary transformations by introducing representation classes from a geometrical approach. It is shown that two bipartite mixed states are equivalent under local…

Quantum Physics · Physics 2008-01-14 Zu-Huan Yu , Xian-Qing Li-Jost , Shao-Ming Fei

We introduce algebraic sets in the complex projective spaces for the mixed states in bipartite quantum systems as their invariants under local unitary operations. The algebraic sets of the mixed state have to be the union of the linear…

Quantum Physics · Physics 2007-05-23 Hao Chen