ar X iv : q ua nt - p h / 01 11 15 1 v 1 2 8 N ov 2 00 1 Coherent States from Combinatorial Sequences

ar X iv : q ua nt - p h / 04 11 17 2 v 1 2 3 N ov 2 00 4 Information and Entropy in Quantum Theory

ar X iv : q ua nt - p h / 02 11 10 6 v 1 1 8 N ov 2 00 2 Harmonic Oscillator , Coherent States , and Feynman Path Integral

The Feynman path integral for the generalized harmonic oscillator is reviewed, and it is shown that the path integral can be used to find a complete set of wave functions for the oscillator. Harmonic oscillators with different (time-dependent) parameters can be related through unitary transformations. The existence of generalized coherent states for a simple harmonic oscillator can then be inte...

ar X iv : q ua nt - p h / 06 08 21 9 v 2 1 5 N ov 2 00 6 Theoretical Study of Fast Light with Short sech Pulses in Coherent Gain Media

We investigate theoretically the phenomenon of so-called fast light in an unconventional regime, using pulses sufficiently short that relaxation effects in a gain medium can be ignored completely. We show that previously recognized gain instabilities, including superfluorescence, can be tolerated in achieving a pulse peak advance of one full peak width.

ar X iv : q ua nt - p h / 06 11 14 4 v 1 1 4 N ov 2 00 6 Geometrical structure of entangled states and secant variety

We show that the secant variety of the Segre variety gives useful information about the geometrical structure of an arbitrary multipartite quantum system. In particular, we investigate the relation between arbitrary bipartite and three-partite entangled states and this secant variety. We also discuss the geometry of an arbitrary general multipartite state.

ar X iv : q ua nt - p h / 05 11 05 9 v 1 7 N ov 2 00 5 Phase Sensitivity of a Mach -

The best performance of a Mach-Zehnder interferometer is achieved with the input state |NT /2+ 1〉|NT /2 − 1〉 + |NT /2 − 1〉|NT /2 + 1〉, being NT the total number of atoms/photons. This gives: i) a phase-shift error confidence C68% = 2.67/NT with ii) a single interferometric measurement. Different input quantum states can achieve the Heisenberg scaling ∼ 1/NT but with higher prefactors and at the...