Control of Quantum Materials: Superconductivity, Magnetism and their Vestiges
| Date/Time: | Monday, 11 Feb 2019 from 4:10 pm to 5:00 pm |
|---|---|
| Location: | Phys 0003 |
| Phone: | 515-294-5441 |
| Channel: | College of Liberal Arts and Sciences |
| Actions: | Download iCal/vCal | Email Reminder |
Title:
Control of quantum materials: superconductivity, magnetism and their vestiges
Abstract:
Quantum materials often display complex phase diagrams with multiple electronically ordered states of matter in proximity to each other. In many cases, these phases are not independent and competing, but rather share a common origin and are therefore intertwined. We discuss a particular case of intertwinement - vestigial order - that is relevant, for example, to the iron based superconductors. Using a powerful group theoretic framework we are able to classify all possible vestigial orders borne out of an underlying primary order, which provides an understanding of the phase diagram based on symmetry alone. This is a crucial first step towards the goal of controlling the properties of such quantum materials. To steer a material towards a desired state, various external tuning parameters are experimentally available, ranging from static perturbations such as pressure or large magnetic fields to dynamic perturbations such as time-dependent electromagnetic fields. We discuss different examples of controlling quantum materials: (i) designing an external effective field that couples to a particular vestigial order parameter, (ii) creating a particular non-equilibrium acoustic phonon distribution function that selectively melts a particular type of electronic order, and (iii) using intense ultrafast terahertz electromagnetic pulses to control superconducting order.
Bio:
Peter P. Orth received a Diploma in Physics at Universitat Heidelberg in 2007, and a Ph.D. at Yale University in 2011 under the supervision of Prof. K. Le Hur. He held postdoctoral positions at the Karlsruhe Institute of Technology (KIT) in the group of Prof. J. Schmalian and at the University of Minnesota in the group of Prof. R. M. Fernandes. At Karlsruhe, he received a Young Investigator Group Grant that allowed him to establish an independent research group working on light-matter interaction and non-equilibrium dynamics of correlated materials. Since coming to Iowa State in 2016, he has continued to explore the properties of quantum materials both in and away from equilibrium and enjoys many fruitful collaborations with experimental colleagues. He is part of the DOE EFRC "Center for the Advancement of Topological Semimetals", where he examines ways to realize desired band topologies by controlling magnetic order.