(b) Write out the equations for the time dependence of ρ11, ρ22, ρ12 and ρ21 assuming that a light field interaction V = -μ12Ee iωt + c.c. couples only levels |1> and |2>, and that the excited levels exhibit spontaneous decay. (8 marks) (c) Under steady-state conditions, find the ratio of populations in states |2> and |3>. (3 marks) (d) Find the slowly varying amplitude ̃ ρ 12 of the polarization ρ12 = ̃ ρ 12e iωt . (6 marks) (e) In the limiting case that no decay is possible from intermediate level |3>, what is the ground state population ρ11(∞)? (2 marks) 2. (15 marks total) In a 2-level atom system subjected to a strong field, dressed states are created in the form |D1(n)> = sin θ |1,n> + cos θ |2,n-1> |D2(n)> = cos θ |1,n> sin θ |2,n-1>

The Quantum Theory of Light

http://cds.cern.ch/record/503806/files/0106045.pdf

New developments in the Casimir effect

Starting from our earlier model [J. Chem. Phys. 66, 1496 (1977)] a simple expression is derived for the radial dependent damping functions for the individual dispersion coefficients C2n for arbitrary even orders 2n. The damping functions are only a function of the Born–Mayer range parameter b and thus can be applied to all systems for which this is known or can be estimated. For H(1S)–H(1S) the results are in almost perfect agreement with the very accurate recent ab initio damping functions of Koide, Meath, and Allnatt. Comparisons with less accurate previous calculations for other systems also show a satisfactory agreement. By adding a Born–Mayer repulsive term [A exp(−bR)] to the damped dispersion potential, a simple universal expression is obtained for the well region of the atom–atom van der Waals potential with only five essential parameters A, b, C6, C8, and C10. The model has been tested for the following representative systems: H2 3Σ, He2, and Ar2 as well as NaK 3Σ and LiHg, which include four che...

An improved simple model for the van der Waals potential based on universal damping functions for the dispersion coefficients

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.

Coherent states: Theory and some Applications

Some methods of describing electron correlation are compared from the point of view of requirements for theoretical chemical models. The perturbation approach originally introduced by Moller and Plesset, terminated at finite order, is found to satisfy most of these requirements. It is size consistent, that is, applicable to an ensemble of isolated systems in an additive manner. On the other hand, it does not provide an upper bound for the electronic energy. The independent electron-pair approximation is accurate to second order in a Moller-Plesset expansion, but inaccurate in third order. A series of variational methods is discussed which gives upper bounds for the energy, but which lacks size consistency. Finally, calculations on some small molecules using a moderately large Gaussian basis are presented to illustrate these points. Equilibrium geometries, dissociation energies, and energy separations between electronic states of different spin multiplicities are describe substantially better by Moller--Plesset theory to second or third order than by Hartree--Fock theory.

Theoretical models incorporating electron correlation

Quantum dynamics with trajectories. Introduction to quantum hydrodynamics

An Overview of LongRange Casimir Interactions L. Spruch. Experimental Studies of High-L Rydberg States in Helium S.R. Lundeen. High Precision Calculations for the Rydberg States of Helium G.W.F. Drake. High Rydberg States of Two-Electron Atoms in Perturbation Theory R.J. Drachman. Long-Range Electromagnetic Forces in Quantum Theory J. Sucher, G. Feinberg. Index.

Long‐Range Casimir Forces: Theory and Recent Experiments on Atomic Systems

Relaxation pathways of photoinduced electronic redistribution at nanostructured semiconductor surfaces are obtained from time-dependent density matrix and ab initio electronic structure methods, giving electronic changes in energy and space over time. They are applied to a Ag cluster on a Si(111) surface, initially photoexcited by a short pulse, and show that the Ag cluster adds surface-localized states that enhance electron transfer. Results on the time evolution of population density distributions in energy and in space, for valence and conduction bands, explore the energy band landscape of a Si slab, with various relaxation pathways ending up in a charge-separated state, with a hole in the Si slab and an electron in the adsorbed Ag cluster. Calculated electronic relaxation times for Si(111)/H are of the same order as experimental values for similar semiconductor systems.

Relaxation of Photoexcited Electrons at a Nanostructured Si(111) Surface

Long-Range Casimir Forces

Part I: Excitation Energy Transfer in Complex Molecular and Biological Systems.- Elisabetta Collini, Carles Curutchet, Tihana Mirkovic, Gregory D.Scholes: Electronic Energy Transfer in Photosynthetic Antenna Systems.- Hui Zhu, Volkhard May: Mixed Quantum Classical Simulations of Electronic Excitation Energy Transfer and Related Optical Spectra: Supramolecular Pheophorbide-a Complexes in Solution.- Eitan Geva, Jianyuan Shang: Conformational Structure and Dynamics from Single-Molecule FRET.- Part II: The Many Facets of DNA.- Eric R. Bittner, Arkadiusz Czader: Quantum Mechanics in Biology: Photoexcitations in DNA.- Dimitra Markovitsi, Thomas Gustavsson: Energy Flow in DNA Duplexes.- O. Kuhn, N. Doslic, G. M. Krishnan, H. Fidder, K. Heyne Anharmonic: Vibrational Dynamics of DNA Oligomers.- Arnab Mukherjee, Richard Lavery, Biman Bagchi, James T. Hynes: Simulation Study of the Molecular Mechanism of Intercalation of the Anti-Cancer Drug Daunomycin into DNA.- Part III: Quantum Dynamics and Transport at Interfaces and Junctions.- Irene Burghardt, Eric R. Bittner, Hiroyuki Tamura, Andrey Pereverzev, John Glenn S. Ramon: Ultrafast Photophysics of Organic Semiconductor Junctions.- D. A. Ryndyk, R. Gutierrez, B. Song, G. Cuniberti: Green Function Techniques in the Treatment of Quantum Transport at the Molecular Scale.- Part IV: New Methods for Open Systems Dynamics.- Ulrich Kleinekathofer: Time-Local Quantum Master Equations and their Applications to Dissipative Dynamics and Molecular Wires.- David A. Micha, Andrew S. Leathers: Reduced Density Matrix Equations for Combined Instantaneous and Delayed Dissipation in Many-Atom Systems, and their Numerical Treatment.- Part V: New Methods for Mixing Quantum and Classical Mechanics.- Robbie Grunwald, Aaron Kelly, Raymond Kapral: Quantum Dynamics in Almost Classical Environments.- S. Bonella, D. F. Coker, D. Mac Kernan, R. Kapral, G. Ciccotti: Trajectory Based Simulations of Quantum-Classical Systems.- Giovanni Ciccotti,Sergio Caprara, Federica Agostini: Do We Have a Consistent Non-Adiabatic Quantum-Classical Statistical Mechanics?.-

David A. Micha

Papers

Quantum dynamics with trajectories. Introduction to quantum hydrodynamics

Long‐Range Casimir Forces: Theory and Recent Experiments on Atomic Systems

Relaxation of Photoexcited Electrons at a Nanostructured Si(111) Surface

Long-Range Casimir Forces

Energy transfer dynamics in biomaterial systems