Author
Da Hsuan Feng
Other affiliations: University of Tennessee, University of Copenhagen, Academia Sinica ...read more
Bio: Da Hsuan Feng is an academic researcher from Drexel University. The author has contributed to research in topics: Fermion & Interacting boson model. The author has an hindex of 23, co-authored 109 publications receiving 2951 citations. Previous affiliations of Da Hsuan Feng include University of Tennessee & University of Copenhagen.
Papers published on a yearly basis
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TL;DR: In this article, a general algorithm for constructing coherent states of dynamical groups for a given quantum physical system is presented, and the result is that the coherent states are isomorphic to a coset space of group geometrical space.
Abstract: In this review, a general algorithm for constructing coherent states of dynamical groups for a given quantum physical system is presented. The result is that, for a given dynamical group, the coherent states are isomorphic to a coset space of group geometrical space. Thus the topological and algebraic structure of the coherent states as well as the associated dynamical system can be extensively discussed. In addition, a quantum-mechanical phase-space representation is constructed via the coherent-state theory. Several useful methods for employing the coherent states to study the physical phenomena of quantum-dynamic systems, such as the path integral, variational principle, classical limit, and thermodynamic limit of quantum mechanics, are described.
1,354 citations
TL;DR: A line of first order phase transitions terminating in a second-order phase transition separates the parameter space of the interacting boson model into a vibrator region [U(59) limit] and a rotor region [SU(3) and O(6) limits].
Abstract: A line of first order phase transitions terminating in a second-order phase transition separates the parameter space of the interacting boson model into a vibrator region [U(59) limit] and a rotor region [SU(3) and O(6) limits]. This first order phase transition line is surrounded by two spinodal lines demarking the limits of metastable nuclear isomers. No other islands of metastability exist in this parameter space.
131 citations
TL;DR: Upper and lower bounds on the ground state energy per nucleon E g N and the free energy per nuclear nucleon F(β) N are constructed for nuclear systems described by pseudospin Hamiltonians in this paper.
121 citations
TL;DR: A fermion dynamical symmetry model that predicts several new dynamical symmetries, one of which has recently been empirically verified, and has limits appropriate to the study of high-spin physics is presented.
Abstract: A fermion dynamical symmetry model is presented. The model has a rich variety of dynamical symmetries, with fully microscopic connections between these dynamical symmetries and the underlying shell structure. In the low angular momentum region, without explicit introduction of bosons, all the dynamical symmetries contained in the phenomenological interacting boson model are recovered. Furthermore, the model predicts several new dynamical symmetries, one of which has recently been empirically verified, and has limits appropriate to the study of high-spin physics.
80 citations
TL;DR: In this paper, the authors suggest that the intensity correlation function could be an important tool in the study of atomic cooperative behavior because it contains predominantly components at 0, $\ifmmode\pm\else\textpm\fi{}4\ensuremath{\Omega}$ in the limit of large Rabi frequency and large cooperation number.
Abstract: We suggest that the intensity correlation function could be an important tool in the study of atomic cooperative behavior because it contains predominantly components at 0, $\ifmmode\pm\else\textpm\fi{}4\ensuremath{\Omega}$ in the limit of large Rabi frequency ($2\ensuremath{\Omega}$) and large cooperation number. This is in contrast with the single-atom prediction where the intensity correlation function contains only frequency components at 0, $\ifmmode\pm\else\textpm\fi{}2\ensuremath{\Omega}$. The master equation for the collective system is solved analytically in the secular approximation.
79 citations
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TL;DR: In this article, a general algorithm for constructing coherent states of dynamical groups for a given quantum physical system is presented, and the result is that the coherent states are isomorphic to a coset space of group geometrical space.
Abstract: In this review, a general algorithm for constructing coherent states of dynamical groups for a given quantum physical system is presented. The result is that, for a given dynamical group, the coherent states are isomorphic to a coset space of group geometrical space. Thus the topological and algebraic structure of the coherent states as well as the associated dynamical system can be extensively discussed. In addition, a quantum-mechanical phase-space representation is constructed via the coherent-state theory. Several useful methods for employing the coherent states to study the physical phenomena of quantum-dynamic systems, such as the path integral, variational principle, classical limit, and thermodynamic limit of quantum mechanics, are described.
1,354 citations
Journal Article•
TL;DR: Squeezed states of the electromagnetic field have been generated by nondegenerate four-wave mixing due to Na atoms in an optical cavity by measuring the total noise level in the deamplified quadrature below the vacuum noise level.
Abstract: Squeezed states of the electromagnetic field have been generated by nondegenerate four-wave mixing due to Na atoms in an optical cavity. The optical noise in the cavity, comprised of primarily vacuum fluctuations and a small component of spontaneous emission from the pumped Na atoms, is amplified in one quadrature of the optical field and deamplified in the other quadrature. These quadrature components are measured with a balanced homodyne detector. The total noise level in the deamplified quadrature drops below the vacuum noise level.
1,217 citations
01 Jan 2006
TL;DR: In this article, the space of isospectral 0Hermitian matrices is shown to be the space in which the number 6) and 7) occur twice in the figure, and the discussion between eqs.(5.14) and (5.15) is incorrect.
Abstract: a ) p. 131 The discussion between eqs. (5.14) and (5.15) is incorrect (dA should be made as large as possible!). b ) p. 256 In the figure, the numbers 6) and 7) occur twice. c ) p. 292 At the end of section 12.5, it should be the space of isospectral 0Hermitian matrices. d ) p. 306 A ”Tr” is missing in eq. (13.43). e ) p. 327, Eq. (14.64b) is 〈Trρ〉B = N(14N+10) (5N+1)(N+3) should be 〈Trρ〉B = 8N+7 (N+2)(N+4)
1,089 citations
TL;DR: In this article, the ground-state odd-proton and odd-neutron spins and parities, proton and neutron pairing gaps, one-and two-Neutron separation energies, quantities related to β -delayed one- and two-NEutron emission probabilities, average energy and average number of emitted neutrons, β -decay energy release and half-life with respect to Gamow-Teller decay with a phenomenological treatment of first-forbidden decays, one and twoproton separation energies and α-decay nuclear half-
956 citations
TL;DR: In this paper, the lattice Boltzmann equation (LBE) is applied to high Reynolds number incompressible flows, some critical issues need to be addressed, noticeably flexible spatial resolution, boundary treatments for curved solid wall, dispersion and mode of relaxation, and turbulence model.
861 citations