Cavity cooling a single charged nanoparticle

The development of laser cooling coupled with the ability to trap atoms and ions in electromagnetic fields, has revolutionised atomic and optical physics, leading to the development of atomic clocks, high-resolution spectroscopy and applications in quantum simulation and processing. However, complex systems, such as large molecules and nanoparticles, lack the simple internal resonances required for laser cooling. Here we report on a hybrid scheme that uses the external resonance of an optical cavity, combined with radio frequency (RF) fields, to trap and cool a single charged nanoparticle. An RF Paul trap allows confinement in vacuum, avoiding instabilities that arise from optical fields alone, and crucially actively participates in the cooling process. This system offers great promise for cooling and trapping a wide range of complex charged particles with applications in precision force sensing, mass spectrometry, exploration of quantum mechanics at large mass scales and the possibility of creating large quantum superpositions.Comment: 8 pages, 5 figures Updated version includes additional references, new title, and supplementary information include

Rossby Wave Propagation into the Northern Hemisphere Stratosphere: The Role of Zonal Phase Speed

Sudden stratospheric warming (SSW) events are to a dominant part induced by upward propagating planetary waves. While theory predicts that the zonal phase speed of a tropospheric wave forcing affects wave propagation into the stratosphere, its relevance for SSW events has so far not been considered. This study shows in a linear wave diagnostic and in reanalysis data that phase speeds tend eastward as waves propagate upward, indicating that the stratosphere preselects eastward phase speeds for propagation, especially for zonal wave number 2. This also affects SSW events: Split SSW events tend to be preceded by anomalously eastward zonal phase speeds. Zonal phase speed may indeed explain part of the increased wave flux observed during the preconditioning of SSW events, as, for example, for the record 2009 SSW event

Party-group relations in new southern European democracies in the crisis era

UID/CPO/04627/2013 PTDC/IVC-CPO/1864/2014publishersversionpublishe

Data for "Coherence of resonant light-matter interaction in the strong-coupling limit"

Data in .mat format underlying the figures of the paper. Each dataset (in the form of a 1D or a 2D array) corresponds to a frame or a subplot as indicated by its label

Mean-field and quantum-fluctuation dynamics in the driven dispersive Jaynes-Cummings model

In this work we investigate the regime of amplitude bistability in the driven dissipative Jaynes-Cummings (JC) model. We study the semiclassical equation dynamics in contrast to entangled cavity-photon and qubit quantum trajectories, discussing our results in the context of an out-of-equilibrium first order quantum dissipative phase transition for a single JC resonator. Finally, we compare the switching process between metastable states for the two system degrees of freedom by examining a single realization of the random qubit vector in the Bloch sphere next to the intracavity amplitude quasi distributions at given time instants

Cavity cooling a single charged nanoparticle

The development of laser cooling coupled with the ability to trap atoms and ions in electromagnetic fields, has revolutionised atomic and optical physics, leading to the development of atomic clocks, high-resolution spectroscopy and applications in quantum simulation and processing. However, complex systems, such as large molecules and nanoparticles, lack the simple internal resonances required for laser cooling. Here we report on a hybrid scheme that uses the external resonance of an optical cavity, combined with radio frequency (RF) fields, to trap and cool a single charged nanoparticle. An RF Paul trap allows confinement in vacuum, avoiding instabilities that arise from optical fields alone, and crucially actively participates in the cooling process. This system offers great promise for cooling and trapping a wide range of complex charged particles with applications in precision force sensing, mass spectrometry, exploration of quantum mechanics at large mass scales and the possibility of creating large quantum superpositions