Why does Xe have a higher boiling point than Ne?
The main interaction between noble gases is Dispersion. (inert gas that's where the name comes from)
Dispersion is larger in heavier atoms. (Considerable larger, 18+18+8 more electrons difference is massive)

an example:
When Interaction energy passes zero point and thermal energy you can have the solid phase. This is why you will not have solid helium.