Joint ICTP-SISSA Colloquium on "Universal theory of strange metals" by Prof. Subir Sachdev

Subir Sachdev is Herchel Smith Professor of Physics at Harvard University, and Miguel Virasoro Visiting International Chair at ICTP. He has been elected to national academies of science in the United States and India, and to the Royal Society in the U.K. He is a recipient of several awards, including the Dirac Medal from ICTP, and the Lars Onsager Prize from the American Physical Society.
Sachdev has made extensive contributions to the theory of the diverse varieties of quantum matter, and of their behavior near quantum phase transitions. Many of these contributions have been linked to experiments, especially to the rich phase diagrams of the copper-oxide high temperature superconductors. Sachdev's research has also exposed remarkable connections between the nature of multi-particle quantum entanglement in certain laboratory materials, and the quantum entanglement in black holes, and these connections have led to new insights on the entropy and radiation of black holes.
Abstract
The “strange metal” is a state of quantum matter, ubiquitous in modern materials, present above the critical temperature of higher temperature superconductors. I will present a universal theory of strange metals, building on the theory of quantum phase transitions in disordered metals. Such transitions involve changes in the shape or volume of the Fermi surface. Random spatial fluctuations in the local position of the quantum critical point, due to impurities, are a key ingredient. The theory uses insights from the solvable Sachdev-Ye-Kitaev model and matches numerous observations.