Performance benchmarking of an ultra-low vibration laboratory to host a commercial millikelvin scanning tunnelling microscope.

Ultra-low temperature scanning tunnelling microscopy and spectroscopy (STM/STS) achieved by dilution refrigeration can provide unrivalled insight into the local electronic structure of quantum materials and atomic-scale quantum systems. Effective isolation from mechanical vibration and acoustic noise is critical in order to achieve ultimate spatial and energy resolution. Here, we report on the design and performance of an ultra-low vibration (ULV) laboratory hosting a customized but otherwise commercially available 40 mK STM.

Experimental study on sound transmission loss of plenum windows.

To investigate the noise reduction mechanism of plenum windows, the paper experimentally studied the influence of the air-gap spacing between two glass panes, the panel thickness, and the opening size on the sound transmission loss (TL). The results show that when the half wavelength of impinged sound is smaller than the air-gap spacing, the TL can be improved by the decrement of the opening sizes and the increment of the glass thickness but varies little with changes in air-gap spacing. When the half wavelength of impinged sound is larger, the modification of the three factors makes little impact on the TL.

An investigation of community noise in high-rise residential environments.

High-rise dwellers in Singapore are often subjected to several community noise sources in close proximity. These include food center, children playground, soccer playground, basketball playground, waste disposal truck, etc. A scientific and reliable approach is required for evaluation of the community noise and its impact on high-rise dwellers.