Physical/Theoretical Chemistry Seminar: Professor Sandeep Sharma, University of Colorado Boulder (Host: Tom Markland)
About the Seminar
"Efficient methods for treating electronic structure of magnetic systems in thermodynamic limit"
Magnetism is a ubiquitous phenomenon that is often found in systems ranging from metalloenzymes to correlated quantum materials. However, describing it theoretically with sufficient accuracy remains one of the outstanding challenges for electronic structure theory. The difficulty can be traced back to the simultaneous presence of strong electron correlation and large relativistic effects. In extended systems, the presence of an Avogadro's number of electrons further complicates the matter. I will begin by describing some of the algorithms that have been developed in my group to tackle these challenges. For example, we can now perform efficient all-electron mean-field calculations in periodic systems, we can also treat relativistic effects such as spin orbit coupling on an equal footing with electron correlation and finally we can calculate the low energy spectrum of these challenging systems containing up to ~50 electrons nearly exactly. By using these techniques in concert we will study the electronic structure of quantum materials known as Iridates and show that there is strong indication that these materials display an unusual quantum phase known as the spin liquid state. The origin of this spin liquid state is not due to geometric frustration but instead due to a novel mechanism that involves the presence of strong spin orbit coupling.