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In quantum computing, knowing the symmetries a given system or state obeys or disobeys is often useful. For example, Hamiltonian symmetries may limit allowed state transitions or simplify learning parameters in machine learning…

Quantum Physics · Physics 2024-07-26 Margarite L. LaBorde , Soorya Rethinasamy , Mark M. Wilde

When initially introduced, a Hamiltonian that realises perfect transfer of a quantum state was found to be analogous to an x-rotation of a large spin. In this paper we extend the analogy further to demonstrate geometric effects by…

Quantum Physics · Physics 2007-05-23 Alastair Kay , Marie Ericsson

The asymptotics of the SU(2) 15j symbol are obtained using coherent states for the boundary data. The geometry of all non-suppressed boundary data is given. For some boundary data, the resulting formula is interpreted in terms of the Regge…

General Relativity and Quantum Cosmology · Physics 2015-05-14 John W. Barrett , Winston J. Fairbairn , Frank Hellmann

This paper analyses quantum mechanics in multiply connected spaces. It is shown that the multiple connectedness of the configuration space of a physical system can determine the quantum nature of physical observables, such as the angular…

High Energy Physics - Theory · Physics 2009-10-30 Vu B Ho , Michael J Morgan

Under the spin-position decoupling approximation, a vector with a phase in 3D orientation space endowed with geometric algebra, substitutes the vector-matrix spin model built on the Pauli spin operator. The standard quantum operator-state…

Quantum Physics · Physics 2022-12-20 Sokol Andoni

We present a mathematical proof of the algorithm allowing to generate all - symmetric and non-symmetric - total angular momentum eigenstates in remote matter qubits by projective measurements, proposed in Maser et al. [Phys. Rev. A 79,…

Quantum Physics · Physics 2015-01-15 C. Ammon , A. Maser , U. Schilling , T. Bastin , J. von Zanthier

We summarize the basics of the loop representation of quantum gravity and describe the main aspects of the formalism, including its latest developments, in a reorganized and consistent form. Recoupling theory, in its graphical…

General Relativity and Quantum Cosmology · Physics 2011-09-09 Roberto De Pietri , C. Rovelli

Physical systems, characterized by an ensemble of interacting elementary constituents, can be represented and studied by different algebras of observables or operators. For example, a fully polarized electronic system can be investigated by…

Quantum Physics · Physics 2009-11-07 R. Somma , G. Ortiz , J. E. Gubernatis , E. Knill , R. Laflamme

On basis of generalized 6j-symbols we give a formulation of topological quantum field theories for 3-manifolds including observables in the form of coloured graphs. It is shown that the 6j-symbols associated with deformations of the…

High Energy Physics - Theory · Physics 2009-10-22 Anna Beliakova , Bergfinnur Durhuus

What can one do with a given tunable quantum device? We provide complete symmetry criteria deciding whether some effective target interaction(s) can be simulated by a set of given interactions. Symmetries lead to a better understanding of…

Quantum Physics · Physics 2015-10-14 Zoltán Zimborás , Robert Zeier , T. Schulte-Herbrueggen , Daniel Burgarth

The kinematical setting of spherically symmetric quantum geometry, derived from the full theory of loop quantum gravity, is developed. This extends previous studies of homogeneous models to inhomogeneous ones where interesting field theory…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Martin Bojowald

The 6j-symbol is a fundamental object from the re-coupling theory of SU(2) representations. In the limit of large angular momenta, its asymptotics is known to be described by the geometry of a tetrahedron with quantized lengths. This…

General Relativity and Quantum Cosmology · Physics 2011-11-16 Valentin Bonzom , Etera R. Livine

Phase-space representations as given by Wigner functions are a powerful tool for representing the quantum state and characterizing its time evolution in the case of infinite-dimensional quantum systems and have been widely used in quantum…

Quantum Physics · Physics 2020-02-24 Bálint Koczor , Robert Zeier , Steffen J. Glaser

In this second paper in a series, we show that the the general statistical approach to nonrelativistic quantum mechanics developed in the first paper yields a representation of quantum spin and magnetic moments based on classical…

Quantum Physics · Physics 2014-09-22 G. H. Goedecke

We theoretically identify observable consequences of spatial and spin symmetries on the dynamics of a small XXZ quantum simulator. Our proposed protocol relies on the choice of suitable initial states, and involves the measurement scheme…

Quantum Physics · Physics 2026-04-08 D. J. Papoular

Simplicial versions of topological abelian gauge theories are constructed which reproduce the continuum expressions for the partition function and Wilson expectation value of linked loops, expressible in terms of R-torsion and linking…

High Energy Physics - Theory · Physics 2008-02-03 David H. Adams

A simple method to calculate Wigner coupling coefficients and Racah recoupling coefficients for U(3) in two group-subgroup chains is presented. While the canonical U(3)->U(2)->U(1) coupling and recoupling coefficients are applicable to any…

Mathematical Physics · Physics 2024-05-14 Phong Dang , Jerry P. Draayer , Feng Pan , Kevin S. Becker

A matrix representation is introduced for stationary beam-like light fields that allows for simultaneous treatment of the orbital angular momentum (OAM) and the second-order state of spatial coherence. This Coherence-OAM matrix is a…

Optics · Physics 2021-03-03 Olga Korotkova , Greg Gbur

Utilizing the previously established general formalism for quantum symmetry reduction in the framework of loop quantum gravity the spectrum of the area operator acting on spherically symmetric states in 4 dimensional pure gravity is…

High Energy Physics - Theory · Physics 2009-10-31 M. Bojowald , H. A. Kastrup

The orbits and the dynamical symmetries for the screened Coulomb potentials and isotropic harmonic oscillators have been studied by Wu and Zeng [Z. B. Wu and J. Y. Zeng, Phys. Rev. A 62,032509 (2000)]. We find the similar properties in the…

Mathematical Physics · Physics 2015-06-11 Yan Li , Fu-Lin Zhang , Jing-Ling Chen