Soft modes, resulting nonanalyticities occur in an entire phase

These are generic soft modes

How big a deal? (After all, these are just standard corrections to scaling!)

II. Interplay with Quantum Critical Behavior

Critical fixed point Phase transition driven by critical soft modes
(OP fluctuations)

Coupling between generic soft modes and OP fluctuations

This can happen at classical transitions, too (e.g., compressible magnets), but

Examples: Various magnetic QPTs in metals