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Related papers: Reduction and Coherent States

200 papers

Coherent states provide an appealing method to reconstruct efficiently a pure state of a quantum mechanical spin s. A Stern-Gerlach apparatus is used to measure (4s+1) expectations of projection operators on appropriate coherent states in…

Quantum Physics · Physics 2007-05-23 Jean-Pierre Amiet , Stefan Weigert

A "squeezed-vacuum" state considered in quantum optics is shown to be realized in the ground-state wavefunction for the bilayer quantum Hall system at the total Landau level filling of $\nu=1/m$ (m: odd integer). This is derived in the…

Mesoscale and Nanoscale Physics · Physics 2009-10-30 T. Nakajima , H. Aoki

We witness experimentally the presence of macroscopic coherence in Gaussian quantum states using a recently proposed criterion (E.G. Cavalcanti and M. Reid, Phys. Rev. Lett. 97, 170405 (2006)). The macroscopic coherence stems from…

The set of two-body reduced states of translation invariant, infinite quantum spin chains can be approximated from inside and outside using matrix product states and marginals of finite systems, respectively. These lead to hierarchies of…

Quantum Physics · Physics 2024-10-29 Vjosa Blakaj , Michael M. Wolf

We extend the concept of classicality in quantum optics to spin states. We call a state ``classical'' if its density matrix can be decomposed as a weighted sum of angular momentum coherent states with positive weights. Classical spin states…

Quantum Physics · Physics 2010-06-23 Olivier Giraud , Petr Braun , Daniel Braun

We extend the definition of generalized coherent states to include the case of time-dependent dispersion. We introduce a suitable operator providing displacement and dynamical rescaling from an arbitrary ground state. As a consequence,…

Quantum Physics · Physics 2007-05-23 Salvatore De Martino , Silvio De Siena , Fabrizio Illuminati

We extend the Bargmann transform to the magnetic pseudodifferential calculus, using gauge-covariant families of coherent states. We also introduce modulation mappings, a first step towards adapting modulation spaces to the magnetic case.

Functional Analysis · Mathematics 2014-06-30 Marius Mantoiu , Radu Purice

We study semiclassical approximations to the time evolution of coherent states for general spin-orbit coupling problems in two different semiclassical scenarios: The limit \hbar to zero is first taken with fixed spin quantum number s and…

Mathematical Physics · Physics 2009-11-10 Jens Bolte , Rainer Glaser

This is a brief review of various families of coherent and squeezed states (and their generalizations) for a charged particle in a magnetic field, that have been constructed for the past 50 years. Although the main attention is paid to the…

Quantum Physics · Physics 2017-11-15 V. V. Dodonov

Using a left multiplication defined on a right quaternionic Hilbert space, we shall demonstrate that various classes of coherent states such as the canonical coherent states, pure squeezed states, fermionic coherent states can be defined…

Mathematical Physics · Physics 2017-06-23 K. Thirulogasanthar , B. Muraleetharan

In this paper we study overcomplete systems of coherent states associated to compact integral symplectic manifolds by geometric quantization. Our main goals are to give a systematic treatment of the construction of such systems and to…

Symplectic Geometry · Mathematics 2012-10-19 William D. Kirwin

Different constructions for Hilbert state space for constrained systems are investigated. Properties of Gaussian states analogous to quantum mechanical Gaussian wave functions are studied. Their evolution for quadratic Hamiltonian case are…

Mathematical Physics · Physics 2008-12-31 O. Yu. Shvedov

It was at the dawn of the historical developments of quantum mechanics when Schr\"odinger, Kennard and Darwin proposed an interesting type of Gaussian wave packets, which do not spread out while evolving in time. Originally, these wave…

Quantum Physics · Physics 2018-08-09 Sanjib Dey , Andreas Fring , Véronique Hussin

In this paper we discuss a proposal of coherent states for Loop Quantum Gravity. These states are labeled by a point in the phase space of General Relativity as captured by a spin-network graph. They are defined as the gauge invariant…

General Relativity and Quantum Cosmology · Physics 2010-09-20 Eugenio Bianchi , Elena Magliaro , Claudio Perini

We construct families of squeezed quantum states on an interval (depending on boundary conditions, we interpret the interval as a circle or as the infinite square potential well) and obtain estimates of position and momentum dispersions for…

Quantum Physics · Physics 2013-04-24 A. S. Trushechkin , I. V. Volovich

We provide an explicit construction for Gazeau-Klauder coherent states related to non-Hermitian Hamiltonians with discrete bounded below and nondegenerate eigenspectrum. The underlying spacetime structure is taken to be of a noncommutative…

High Energy Physics - Theory · Physics 2012-11-21 Sanjib Dey , Andreas Fring

We study coherent states for Bianchi type I cosmological models, as examples of semiclassical states for time-reparametrization invariant systems. This simple model allows us to study explicitly the relationship between exact semiclassical…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Brett Bolen , Luca Bombelli , Alejandro Corichi

We define generalised Gaussian states for quantum cosmological models based on the $\mathfrak{su(1,1)}$ algebra, with particular emphasis on its realisation in group field theory for a single field mode, and study their semiclassical…

General Relativity and Quantum Cosmology · Physics 2024-03-26 Andrea Calcinari , Steffen Gielen

We investigate the systematic use of the Schwinger representation, by virtue of which two boson fields are equivalent to an effective spin, for casting multimode squeezed states into multipartite spin entangled states. The motivation for…

Quantum Physics · Physics 2015-06-17 Niranjan Sridhar , Olivier Pfister

The dissipative dynamics of Gaussian squeezed states (GSS) and coherent superposition states (CSS) are analytically obtained and compared. Time scales for sustaining different quantum properties such as squeezing, negativity of the Wigner…

Quantum Physics · Physics 2009-11-13 L. A. M. Souza , M. C. Nemes , M. França Santos , J. G. Peixoto de Faria