Abstract:

Toy models of strongly interacting electrons bound to a lattice are used in condensed matter physics to understand electronic properties of quantum materials at low temperatures. One relatively simple model is even believed to have the ingredients necessary to describe high-temperature superconductivity and other exotic phases of matter. In this talk, I will introduce the model, which is well known to promote anti-ferromagnetism (the opposite alignment of electron spins on neighboring lattice sites), and show that under the right conditions, it can also host ferromagnetism. I will discuss two phenomena that drive the system on different geometries to ferromagnetic states and present exact numerical results for spin correlations and other thermodynamic properties in support of the claims. Finally, I will discuss the relevance of our results to recent observations with ultracold atoms in optical lattices.

Bio:

Dr. Khatami received his PhD in physics from the University of Cincinnati in 2009. After several research positions at Louisiana State University, Georgetown University, UC Santa Cruz and UC Davis, he joined San Jose State University in 2014 where he is now a Professor in physics. His numerical simulations of quantum many-body systems have been a part of several collaborations with atomic, molecular, and optical experimentalists. His group has also been exploring the use of machine learning tools in quantum many-body physics. Dr. Khatami has been a KITP Scholar and Fellow since 2016. In 2018, he was awarded San Jose State University's Early Career Investigator Award, and this year, was named Dean's Scholar for research excellence.

Before the talk (~3:45pm), tea and coffee will be served outside 116 Weniger.

After the talk, there will be a reception with food and drink in 247 Weniger.