Charge orders and charge fluctuations have been ubiquitously observed in the phase diagram of Cuprate superconductors.  We will review the experimental status of these various observations, differentiating the under-doped region and the optimally-doped and over-doped ones.  Various theories have been advanced to explain the presence of these orders and their implication for our understanding of the pseudo-gap, from the idea of “vestigial order” to the one of “fluctuating Pair Density Wave (PDW)”. We will discuss these theoretical approaches in direct comparison with experiments.  We will then introduce a proposal of “fractionalization of a PDW”  in order to explain the pseudo-gap state. We will show that this idea produces a strong phenomenology, especially ARPES experiments, and giving a clue for the puzzling transport properties recently reported in the optimally doped and over-doped regions. We will then focus on the strange metal phase of those compounds and make a proposal for electric transport in this phase.

The seminar will take place in person at the IIP Seminar Room II. It will not be streamed online, nor recorded.