English
Related papers

Related papers: Infinite operator-sum representation of density op…

200 papers

By introducing thermal entangled state representation which can map master equations of density operator in quantum statistics as state vector evolution equations and using dissipative interaction picture we solve the master equation of J-C…

Quantum Physics · Physics 2014-02-12 Seyed Mahmoud Ashrafi , Mohammad Reza Bazrafkan

For states in infinite dimensional Hilbert spaces entanglement quantities like the entanglement of distillation can become infinite. This leads naturally to the question, whether one system in such an infinitely entangled state can serve as…

Quantum Physics · Physics 2007-05-23 M. Keyl , D. Schlingemann , R. F. Werner

By introducing the thermo entangled state representation, we convert the calculation of Wigner function (WF) of density operator to an overlap between "two pure" states in a two-mode enlarged Fock space. Furthermore, we derive a new WF…

Quantum Physics · Physics 2015-05-20 Li-yun Hu , Zheng-lu Duan , Xue-xiang Xu , Zi-sheng Wang

The expression for the density operator of the damped harmonic oscillator is derived from the master equation in the framework of the Lindblad theory for open quantum systems. Then the von Neumann entropy and effective temperature of the…

Quantum Physics · Physics 2007-05-23 A. Isar

A closed expression for the density operator of the damped harmonic oscillator is extracted from the master equation based on the Lindblad theory for open quantum systems. The entropy and effective temperature of the system are subsequently…

High Energy Physics - Theory · Physics 2007-05-23 A. Isar

In this paper we develop a convergence analysis in an infinite dimensional setting of the Levenberg-Marquardt iteration for the solution of a hybrid conductivity imaging problem. The problem consists in determining the spatially varying…

Analysis of PDEs · Mathematics 2012-11-27 Guillaume Bal , Wolf Naetar , Otmar Scherzer , John Schotland

In this paper, by virtue of the entangled state representation we concisely derive some new operator identities regarding to two-variable Hermite polynomial (TVHP). By them and the technique of integration within an ordered product (IWOP)…

Quantum Physics · Physics 2010-11-30 Hong-yi Fan , Hong-chun Yuan

We show that any arbitrary time-dependent density operator of an open system can always be described in terms of an operator-sum representation regardless of its initial condition and the path of its evolution in the state space, and we…

Quantum Physics · Physics 2009-11-10 D. M. Tong , L. C. Kwek , C. H. Oh , Jing-Ling Chen , L. Ma

We show that a mixed state $\rho=\sum_{mn}a_{mn}|m> < n|$ can be realized by an ensemble of pure states $\{p_{k}, |\phi_{k} > \}$ where $|\phi_{k}>=\sum_{m}\sqrt{a_{mm}}e^{i\theta_{m}^{k}}|m>$. Employing this form, we discuss the relative…

Quantum Physics · Physics 2007-05-23 Yi-Xin Chen , Dong Yang

In this work, the definition of the density operator on quantum states in Hilbert spaces and some of its aspects relevant in thermodynamics and information-theoretical entropy calculations are given. In this framework, a physical model…

Mathematical Physics · Physics 2017-09-25 Isiaka Aremua , Mahouton Norbert Hounkonnou , Ezinvi Baloitcha

We show how to simulate numerically both the evolution of 1D quantum systems under dissipation as well as in thermal equilibrium. The method applies to both finite and inhomogeneous systems and it is based on two ideas: (a) a representation…

Other Condensed Matter · Physics 2007-05-23 F. Verstraete , J. J. Garcia-Ripoll , J. I. Cirac

Selfadjoint and maximal dissipative extensions of a non-densely defined symmetric operator $S$ in an infinite-dimensional separable Hilbert space are considered and their compressions on the subspace ${\rm \overline{dom}\,} S$ are studied.…

Functional Analysis · Mathematics 2024-09-17 Yu. M. Arlinski\uı

It is shown that the the quantum phase space distributions corresponding to a density operator $\rho$ can be expressed, in thermofield dynamics, as overlaps between the state $\mid \rho >$ and "thermal" coherent states. The usefulness of…

Quantum Physics · Physics 2008-11-26 S. Chaturvedi , V. Srinivasan , G. S. Agarwal

Fleming's inequality is generalized to the decay function of mixed states. We show that for any symmetric hamiltonian $h$ and for any density operator $\rho$ on a finite dimensional Hilbert space with the orthogonal projection $\Pi$ onto…

Quantum Physics · Physics 2010-11-15 Florian Fröwis , Gebhard Grübl , Markus Penz

In the preceding paper (arXiv : 0710.2724 [quant-ph]) we have constructed the general solution for the master equation of quantum damped harmonic oscillator, which is given by the complicated infinite series in the operator algebra level.…

Quantum Physics · Physics 2015-05-13 Kazuyuki Fujii , Tatsuo Suzuki

We introduce the entangled coherent state representation, which provides a powerful technique for efficiently and elegantly describing and analyzing quantum optics sources and detectors while respecting the photon number superselection rule…

Quantum Physics · Physics 2007-05-23 Barry C. Sanders , Stephen D. Bartlett , Terry Rudolph , Peter L. Knight

The quantum state for the spatial degrees of freedom of photons propagating through turbulence is analyzed. The turbulent medium is modeled by a single phase screen for weak scintillation conditions and by multiple phase screens for general…

Quantum Physics · Physics 2015-06-19 Filippus S. Roux

We solve analytically master equations that describe a cavity filled with a kerr medium, taking into account the dissipation induced by the environment, and parametric down conversion processes. We use superoperator techniques.

We present techniques to construct the Deutsch-Hayden representation for quantum field operators and apply them to an entangled state of identical nonrelativistic spin-1/2 fermions localized in well-separated spatial regions. Using these…

Quantum Physics · Physics 2023-01-11 Mark A. Rubin

We present error estimates of the fully semi-Lagrangian scheme with high-order interpolation operators, solving the initial value problems for the one-dimensional nonlinear diffusive conservation laws, including the Burgers equations. We…

Numerical Analysis · Mathematics 2025-09-22 Haruki Takemura
‹ Prev 1 2 3 10 Next ›