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We propose a feedback scheme to control the vibrational motion of a single trapped particle based on indirect measurements of its position. It results the possibility of a motional phase space uncertainty contraction, correponding to cool…

Quantum Physics · Physics 2008-12-18 Stefano Mancini , David Vitali , Paolo Tombesi

A one-parameter random matrix model is proposed for describing the statistics of the local amplitudes and phases of electron eigenfunctions in a mesoscopic quantum dot in an arbitrary magnetic field. Comparison of the statistics obtained…

Condensed Matter · Physics 2009-10-28 E. Kanzieper , V. Freilikher

The generalized pseudospectral method is employed for the accurate calculation of eigenvalues, densities and expectation values for the spiked harmonic oscillators. This allows \emph{nonuniform} and \emph{optimal} spatial discretization of…

Quantum Physics · Physics 2015-06-16 Amlan K. Roy

Principal component analysis (PCA) requires the computation of a low-rank approximation to a matrix containing the data being analyzed. In many applications of PCA, the best possible accuracy of any rank-deficient approximation is at most a…

Computation · Statistics 2010-06-04 Vladimir Rokhlin , Arthur Szlam , Mark Tygert

We present a technique which allows us to solve the Random Phase Approximation equations with finite-range interactions and treats the continuum part of the excitation spectrum without approximations. The interaction used in the…

Nuclear Theory · Physics 2011-05-13 V. De Donno , G. Co' , M. Anguiano , A. M. Lallena

We review the methods based on expectation value coupled cluster formalism - a common framework for the derivation of properties: the ground-state average value of an observable, cumulants of the second-order reduced density matrices,…

Chemical Physics · Physics 2021-11-15 Aleksandra M. Tucholska , Robert Moszynski

The prediction of electronic structure for strongly correlated molecules represents a promising application for near-term quantum computers. Significant attention has been paid to ground state wavefunctions, but excited states of molecules…

Quantum Physics · Physics 2025-01-08 Harper R. Grimsley , Francesco A. Evangelista

The molecular dipole moment and magnetic hyperfine structure constant demand an accurate wavefunction far from the nucleus and in near nuclear region, respectively. We, therefore, employ the so-called Z-vector method in the domain of…

Chemical Physics · Physics 2015-03-31 Sudip Sasmal , Himadri Pathak , Malaya K. Nayak , Nayana Vaval , Sourav Pal

The ground-state permanent dipole moments (PDMs) and molecular dipole polarizabilities (DPs) of open-shell alkaline-earth monofluorides, and atomic DPs of alkaline-earth- and fluorine atoms are reported at the Kramers-restricted…

Atomic Physics · Physics 2019-05-22 Renu Bala , H. S. Nataraj , Malaya K. Nayak

Stein operators allow to characterise probability distributions via differential operators. Based on these characterisations, we develop a new method of point estimation for marginal parameters of strictly stationary and ergodic processes,…

Statistics Theory · Mathematics 2024-12-05 Bruno Ebner , Adrian Fischer , Robert E. Gaunt , Babette Picker , Yvik Swan

We consider the N-body problem in a layered geometry containing cold polar molecules with dipole moments that are polarized perpendicular to the layers. A harmonic approximation is used to simplify the hamiltonian and bound state properties…

Quantum Gases · Physics 2012-04-02 J. R. Armstrong , N. T. Zinner , D. V. Fedorov , A. S. Jensen

We address the computation of ground-state properties of chemical systems and realistic materials within the auxiliary-field quantum Monte Carlo method. The phase constraint to control the fermion phase problem requires the random walks in…

Strongly Correlated Electrons · Physics 2017-11-28 Mario Motta , Shiwei Zhang

Much of the mathematical development of quantum field theory has been in support of determining the S-matrix in order to calculate scattering cross sections. However there is also an interest in determining how expectation values of field…

General Physics · Physics 2014-07-24 Dan Solomon

We present a new methodology to analyze complicated multi-physics simulations by introducing a fictitious parameter. Using the method, we study quantum mechanical aspects of an organic molecule in water. The simulation is variationally…

Chaotic Dynamics · Physics 2007-05-23 Toshiya Takami , Jun Maki , Jun-ichi Ooba , Taizo Kobayashi , Rie Nogita , Mutsumi Aoyagi

In this work we reexamine quantum electrodynamics of atomic eletrons in the Coulomb gauge in the dipole approximation and calculate the shift of atomic energy levels in the context of Dalibard, Dupont-Roc and Cohen-Tannoudji (DDC) formalism…

Atomic Physics · Physics 2009-11-07 J. L. Tomazelli , L. C. Costa

We present a new method that accurately approximates the shell-model ground-state by products of suitable states. The optimal factors are determined by a variational principle and result from the solution of rather low-dimensional…

Nuclear Theory · Physics 2007-05-23 T. Papenbrock , D. J. Dean

We have developed a method for constructing spectral approximations for convolution operators of Fredholm type. The algorithm we propose is numerically stable and takes advantage of the recurrence relations satisfied by the entries of such…

Numerical Analysis · Mathematics 2024-05-15 Xiaolin Liu , Kuan Deng , Kuan Xu

We present a quantum-classical hybrid random power method that approximates a ground state of a Hamiltonian. The quantum part of our method computes a fixed number of elements of a Hamiltonian-matrix polynomial via quantum polynomial…

Quantum Physics · Physics 2025-04-17 Taehee Ko , Hyowon Park , Sangkook Choi

Numerical methods based on matrix product states (MPSs) are currently the de facto standard for calculating the ground-state properties of (quasi-)one-dimensional quantum many-body systems. While the properties of the low-lying excitations…

Strongly Correlated Electrons · Physics 2025-04-16 Jesse J. Osborne , Ian P. McCulloch

The RPA long range correlations are known to play a significant role in understanding the depletion of single particle-hole states observed in (e, e') and (e, e'p) measurements. Here the Random Phase Approximation (RPA) theory, implemented…

Nuclear Theory · Physics 2009-11-11 M. Dupuis , S. Karataglidis , E. Bauge , J. P. Delaroche , D. Gogny
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