室溫的超導體存在嗎?

Not sure yet, but there has been a publication in 2008 which reports the high transition temperature of Al anionic nanoclusters around 200K. So, it may be possible that one day people can find superconductors whose Tc are close to RT.

Ref: Journal of Superconductivity and Novel Magnetism, Vol. 21, p.163-166 (2008)