🚀 go-pugleaf

Hi all.

I have a couple of questions that I was wondering if anybody here could answer.

First off, I'm curious about whether NbN is a superconductor. I just saw a
paper which said it was, and that its acoustic attenuation was dramatically
effected by the superconducting transition, falling to zero a degrees beneath
the Tc. I had some reason to believe that NbN was NOT a superconductor
and I'd appreciate it if anybody here can clarify that for me.

Secondly, I'm curious as to how high the frequencies of acoustic waves can
get before the attenuation gets too significant. In NbN, for example, where
surface acoustic attenuation falls to zero beneath Tc at 700MHz, how high
can the frequencies be raised before this zero attenuation no longer applies?

What I am really looking for is a material or combination of materials where
at about 4.2K, acoustic waves (SAW, BAW, or anything else) can be generated,
transmitted 100 microns, and received with losses under 10 dB. I also need it
to support frequencies up to 300 GHz. If piezoelectric superconductors have
nearly zero acoustic attenuation, that would help dramatically.

Thanks.

Jason W. Solinsky