Magnetic Force Microscopy Specifications in attoDRY1100 on par with Liquid Cryostats
In this application note, we show examples of magnetic force microscopy measurements performed in the pulse-tube based, fully automated attoDRY1100 cooling system. The attoDRY1100 cryogenfree magnet system redefines the state of the art of MFM, with specifications close to those reached in a regular liquid bath cryostat.
Significant decrease of the optical losses at cryogenic temperature with the attoCFM I
Plasmonic structures present a relevant way to enhance the fluorescence of nanoemitters as colloidal semiconductor nanocrystals. However, they show high optical losses in the visible range which reduce the radiative quantum efficiency. In order to study the evolution of optical losses between 4K and room temperature, the group of Jean-Pierre Hermier at the Université de Versailles Saint-Quentin-en-Yvelines, France, performed time resolved experiments on nanocrystals coupled to a flat gold film. Thanks to the high stability of attoCFM I cooled by a closed cycle cryostat, the attoDRY1100, they recorded the photoluminescence decay at base temperature (4K) of a single CdSe/CdS nanocrystal directly deposited on the flat gold film without any drift for several hours. This is shown by the temporal trace of the intensity in the figure.
As a result of their work and in comparison to the predictions of a theoretical model, the radiative quantum efficiency is enhanced by a factor of three. This motivates for further studies at cryogenic temperatures, especially in the domain of quantum optics for which the reduction of the temperature also results in an improvement of the emitter optical properties.
A. Coste, et al.; Phys. Rev. B 96, 195416 (2017)