261 research outputs found
The Minimum-Uncertainty Squeezed States for for Atoms and Photons in a Cavity
We describe a six-parameter family of the minimum-uncertainty squeezed states
for the harmonic oscillator in nonrelativistic quantum mechanics. They are
derived by the action of corresponding maximal kinematical invariance group on
the standard ground state solution. We show that the product of the variances
attains the required minimum value 1/4 only at the instances that one variance
is a minimum and the other is a maximum, when the squeezing of one of the
variances occurs. The generalized coherent states are explicitly constructed
and their Wigner function is studied. The overlap coefficients between the
squeezed, or generalized harmonic, and the Fock states are explicitly evaluated
in terms of hypergeometric functions. The corresponding photons statistics are
discussed and some applications to quantum optics, cavity quantum
electrodynamics, and superfocusing in channeling scattering are mentioned.
Explicit solutions of the Heisenberg equations for radiation field operators
with squeezing are found.Comment: 27 pages, no figures, 174 references J. Phys. B: At. Mol. Opt. Phys.,
Special Issue celebrating the 20th anniversary of quantum state engineering
(R. Blatt, A. Lvovsky, and G. Milburn, Guest Editors), May 201
Density Functional Theory for a Confined Fermi System with Short-Range Interaction
Effective field theory (EFT) methods are applied to density functional theory
(DFT) as part of a program to systematically go beyond mean-field approaches to
medium and heavy nuclei. A system of fermions with short-range, natural
interactions and an external confining potential (e.g., fermionic atoms in an
optical trap) serves as a laboratory for studying DFT/EFT. An effective action
formalism leads to a Kohn-Sham DFT by applying an inversion method
order-by-order in the EFT expansion parameter. Representative results showing
the convergence of Kohn-Sham calculations at zero temperature in the local
density approximation (LDA) are compared to Thomas-Fermi calculations and to
power-counting estimates.Comment: 36 pages, 20 figures, RevTeX
Coherent States for Canonical Quantum General Relativity and the Infinite Tensor Product Extension
We summarize a recently proposed concrete programme for investigating the
(semi)classical limit of canonical, Lorentzian, continuum quantum general
relativity in four spacetime dimensions. The analysis is based on a novel set
of coherent states labelled by graphs. These fit neatly together with an
Infinite Tensor Product (ITP) extension of the currently used Hilbert space.
The ITP construction enables us to give rigorous meaning to the infinite volume
(thermodynamic) limit of the theory which has been out of reach so far.Comment: 37 p., latex2e, no figure
- …