Generalized coherent state representation of Bose-Einstein condensates

We show that the quantum many-body state of Bose-Einstein condensates (BEC) consistent with the time-dependent Hartree-Fock-Bogoliubov (TDHFB) equations is a generalized coherent state (GCS). At zero temerature, the non-condensate density and the anomalous non-condensate correlation are not independent, allowing us to elimiate one of the three variables in the TDHFB.Comment: Submitted to Phys. Rev. A. No figures. Revised version fixes several minor typos, and adds to some discussions; no change to the conclusio

Ultrafast laser inscribed integrated photonics: material science to device development

Detailed studies of intense light – material interactions has led to new insights into fs laser induced refractive index change in a range of glass types. This body of knowledge enables the development of advanced processing methodologies, resulting in novel planar and 3D guided wave devices. We will review the chemistry and morphology associated with fs laser induced refractive index change in multi-component glasses such as ZBLAN, phosphates and silicates, and discuss how these material changes inform our research programs developing a range of active and passive lightwave systems.S. Gross, T. D. Meany, A. Arriola, C. Miese, R. J. Williams, Y. Duan, Q. Liu, I. Spaleniak, M. Ams, P. Dekker, N. Jovanovic, A. Fuerbach, M. Ireland, M. J. Steel, D. G. Lancaster, H. Ebendorff Heidepriem, T. M. Monro, and M. J. Withfor

Gaussian quantum operator representation for bosons

We introduce a Gaussian quantum operator representation, using the most general possible multimode Gaussian operator basis. The representation unifies and substantially extends existing phase-space representations of density matrices for Bose systems and also includes generalized squeezed-state and thermal bases. It enables first-principles dynamical or equilibrium calculations in quantum many-body systems, with quantum uncertainties appearing as dynamical objects. Any quadratic Liouville equation for the density operator results in a purely deterministic time evolution. Any cubic or quartic master equation can be treated using stochastic methods