What is 'High' Temperature superconductivity?
Based on what I've heard...
Superconductivity can only be achieved at incredibly low temperatures (low to mid double digit Kelvin temperatures). High temperature superconductivity is superconductivity that can be achieved at or near room temperature.
Not at. Highest critical temperature is (IIRC) still over 100K under room temperature. If you have more specific questions I'm sure Zz can answer those.
"High" temperature superconductors are those achieving superconducitivity at Tc greater than 50 K. That's all.
Why 50 K? It's arbitrary. It was thought that Tc couldn't go beyond 35 or 40 K at best before 1986. Then the cuprate superconductors were discovered and all hell broke loose.
Oh really? I thought it was only part of hell...
The term HTS may also refer to a particular class of superconductors, which demonstrates high critical temperature (actually, there is only one) But this particular materials may be called HTS even if they have rather low critical temperature. They are called so to emphasize that they have a crystal structure and a superconducting mechanism similar to their relatives. These materials are usually very poor conductors in their nonsuperconducting state and very brittle. Their mechanical characteristics are similar to those of ceramics and they have a layered crystal structure. Sometimes they are called "bad" metals.
Separate names with a comma.