New Scenario for high-Tc cuprates: electronic topological transition as a motor for anomalies in the underdoped regime

This is a particularly exciting time for high-Tc. The experimental knowledge converges. Almost all experiments, nuclear magnetic resonance (NMR), angle resolved photoemission spectroscopy (ARPES), tunneling spectroscopy etc., provide an evidence for the existence of a characteristic energy scale T*(d) in the underdoped regime (d is hole doping). Below and around the line T*(d) the "normal " state (i.e. above Tc) has properties fundamentally incompatible with the present understanding of metal physics. The field has reached the point when a consistent theory is needed to understand this experimentally well defined but theoretically exotic metallic behaviour and its relevance to high Tc superconductivity. We show that these phenomena can be naturall