Quantum Kerr oscillators' evolution in phase space : Wigner current, symmetries, shear suppression and special states

©2019 American Physical Society. All rights reserved. This is the author-prepared / formatted version of an article accepted for publication in Physical Review A. The definitive publisher-authenticated version is available online at: https://doi.org/10.1103/PhysRevA.99.032104The creation of quantum coherences requires a system to be anharmonic. The simplest such continuous one-dimensional quantum system is the Kerr oscillator. It has a number of interesting symmetries we derive. Its quantum dynamics is best studied in phase space, using Wigner's distribution W and the associated Wigner phase space current J. Expressions for the continuity equation governing its time evolution are derived in terms of J and it is shown that J for Kerr oscillators follows circles in phase space. Using J we also show that the evolution's classical shear in phase space is quantum suppressed by an effective "viscosity." Quantifying this shear suppression provides measures to contrast classical with quantum evolution and allows us to identify special quantum states.Peer reviewe

Imprinting interference fringes in massive optomechanical systems

An interferometric scheme for the creation of momentum superposition states of mechanical oscillators, using a quantum mirror kicked by free photons is analyzed. The scheme features ultra-fast preparation with immediate detection and should allow for the observation of signatures of momentum superpositions in a massive macroscopic system at non-zero temperatures. It is robust against thermalized initial states, displacement and movement, mirror imperfections, and the measurements' back-actions.Comment: 4 pages, 3 figures, 7 subfigure

Tradizione in trasformazione: templi greci come luoghi di memoria tra ellenismo ed età imperiale

Ausgehend von zwei Fallbeispielen, dem Apollontempel im Letoon von Xanthos und demjenigen von Kyrene, geht der Beitrag der Frage nach, welche Rolle Tempelbauten für das Selbstverständnis griechischer bzw. hellenisierter Gemeinwesen spielten. In beiden Fällen sind ältere Sakralbauten, oder zumindest substanzielle Teile von solchen, im Innern jüngerer Tempel erhalten geblieben. Es scheint hier eine Strategie fassbar, mit der einerseits das historische Erbe der jeweiligen Gemeinwesen herausgestellt, andererseits der Anschluss an zeitgenössische Trends der Baukunst gesucht wird. Diese ‚bewahrende Modernisierung‘ dient nicht zuletzt dazu, politische und soziale Positionen in Zeiten des Umbruchs, namentlich im Prozess der Eingliederung in die hellenistischen und römischen Großreiche zu behaupten