Dr. Stephen Hill
Title of Research: Development and Application of Unique High-Field Magnetic Resonance Techniques
Description of Research Area: A broad range of opportunities exist for postdoctoral researchers in the Hill group, including the development of cutting-edge high-field magnetic resonance techniques, and applications of these methodologies in diverse research fields spanning from biophysics and biochemistry, to inorganic and materials chemistry, all the way to condensed matter physics. The Hill lab is based at the National High Magnetic Field Laboratory at Florida State University, which is the world’s premier facility for research in high magnetic fields. As such, the group is currently working on the development of: very high-field/frequency (>30 Tesla and up to 1 THz), high-resolution Electron Paramagnetic Resonance (EPR) capabilities; high-power, broadband (~1 kW & 1 GHz bandwidth) pulsed EPR hardware operating at uniquely high frequencies (95 GHz and above), including integration of arbitrary waveform excitation; high-pressure (up to 3 GPa) single-crystal EPR methodologies; and instrumentation for Dynamic Nuclear Polarization (DNP) enhanced Nuclear Magnetic Resonance (NMR) in solids and solutions at record high magnetic fields (14.1 Tesla). Importantly, the group has made its reputation by publishing extensively using these unique methods in the following research fields: molecular nanomagnetism, including the development of single-molecule magnets and molecular spin qubits; low-dimensional and frustrated magnetism; organic magnets, conductors and superconductors; magnetochemistry and coordination chemistry. The most recent thrusts within the group include fundamental studies of the Overhauser DNP NMR enhancement mechanism in organic solutions, the characterization/optimization of DNP enhancement agents (including radicals and lanthanides), and the application of pulsed high-field EPR to biophysical problems.
Special Research & Career Skills: While it is anticipated that postdoctoral applicants would have experience in one or more of the above research topics, training could be provided in any of the other areas, as needed or requested. Training in grant writing, preparation of research articles/reports, and presentation skills would also be provided.
Dr. Jose Mendoza-Cortes
Title of Research: Materials discovery and Materials Design for energy applications by machine learning algorithms
Description of Research Area:
The Mendoza-Cortes groups has have been pioneering the Materials by Design over the last 12 years using numerous mathematical concepts in combination with new atomistic simulations and experiments. Our lab currently has 19 publications which have been cited around 4,912 times (source: Google Scholar). This is perhaps the highest citations number for someone who is under 32 years old.
Theoretical and computational studies are integral parts of research in interdisciplinary areas of science and technology. The advent of powerful modern computers, developments in sophisticated algorithms and theories, and access to a large amount of data from previous studies suggest that in the future, computational techniques would continue to play a dominant role in both fundamental and applied research. However, currently used computational methods have well-known limitations. Although a few groups have introduced automated reaction search algorithms and high-throughput studies with some success, myriads of unique possible pathways and combinations should be investigated by using accurate theoretical methods to furnish a reliable theoretical prediction of the reaction outcome. This makes the calculations prohibitively expensive, highly time consuming, and tedious compared to the actual experiments.
Inspiring from the recent success of deep-learning and artificial neural networks, we propose to apply them for the designing of novel materials for energy related applications. We would like to apply the principles of machine leaning to design solar energy materials, batteries, and energy storage devices. We would use existing machine learning algorithms and also develop our own code to tackle with the challenging problems in chemistry and materials science. A combination of fields would help us to analyze, understand, and rationalize the structure-activity relationships of numerous candidate systems and select the optimum ones for the experimental realization.
Special Research & Career Skills:
Expertise on electronic structure calculations for both molecular and periodic systems, scripting/programming expertise, multiscale and atomistic simulation techniques, engineering devices, Monte-Carlo methods, reactive molecular dynamics, and force-field based simulations.
Assistance with Job opportunities, training to submit proposals, formal coaching to present research findings.
Dr. Dragana Popovic
Title of Research: Experimental Condensed Matter Physics
Description of Research Area: The goal of our current research is to understand the nature and the dynamics of charge-ordered states in the presence of other, competing phases in strongly correlated materials, especially in the vicinity of quantum critical points. Indeed, the role of collective fluctuations near quantum critical points is increasingly recognized as one of the key questions in the physics of strongly correlated systems, but there have been few studies of charge, as opposed to spin, dynamics. Our work seeks to close this gap by using time-resolved charge transport measurements (e.g. resistance noise spectroscopy) on very long time scales, which in our prior work proved to be powerful probes of out-of-equilibrium or glassy charge dynamics, quantum critical points, and novel, intermediate phases. These time-resolved techniques, combined with various linear and nonlinear electrical transport measurements, are used to reveal and clarify the interplay of strong electronic correlations and disorder in two-dimensional (2D) and quasi-2D systems, and the nature of various ground states and quantum critical points.
Topics include quantum phase transitions, such as the metal-insulator transition in 2D semiconductor heterostructures and the magnetic-field-tuned superconducting transition in copper-oxide high-temperature superconductors; structural transitions in cuprates and iron pnictides; charge dynamics (glassy freezing and other out-of-equilibrium behavior); interplay of charge order and superconductivity; superconducting fluctuations and vortex dynamics; mesoscopic effects. Experiments are performed over a wide range of temperatures, from the millikelvin regime up to room temperature, and over a wide range of magnetic fields. The Popovic lab is located at the National High Magnetic Field Laboratory (NHMFL) at Florida State University, which is the world’s premier facility for research in high magnetic fields. In addition to the magnets and cryostats in our own lab, we regularly perform experiments in the NHMFL’s unique high-field magnets up to 45 T.
Special Research & Career Skills: Postdoctoral applicants are expected to have experience in one or more of the above research topics or relevant experimental techniques. Training would be provided in other areas, as needed. In addition, training in preparation of research articles, reports, magnet time requests and grant proposals, as well as presentation skills would also be provided.
Website Links: Magnetic Lab Profile
Dr. Wan Kyu Park
Title of Research: Electron spectroscopy of emergent and topological phases of matter
Description of Research Area: The research area for a postdoctoral scholar will be centered on three core research themes in condensed matter physics: superconductivity, strong correlations, and topological phases. Two of the crucial questions in forefront research are: i) How do the novel phases emerge in strongly correlated systems?; ii) What is the nature of correlated topological phases?
For the first question, an archetypal system is Kondo (or Anderson, in a broader context) lattices, which consist of itinerant and localized electrons. Although the behavior each of the two ingredients is well understood separately, the nature of their combined ground state is not always predictable. The detailed hybridization process resulting in novel ground states has long been investigated. Nonetheless, its microscopic understanding via electron spectroscopic measurements is still largely lacking. Also, it is not well understood why and how quite distinct ground states emerge out of systems that contain seemingly similar ingredients.
Topological phases defy descriptions based on the conventional Landau-Ginzburg paradigm where symmetry breaking plays a central role. Instead, here the topological aspects of band structures are important. Topological insulators are a well-established example, in which protected metallic states exist on surfaces while the bulk is insulating. In contrast to the weakly correlated topological insulators, the counterparts in correlated systems, Samarium Hexaboride being a prototype, have revealed many challenges in understanding their topological nature.
The postdoc’s research will largely aim at addressing the two questions mentioned above using two specialty techniques, namely, planar tunneling and point-contact spectroscopies. This research will not only bring novel insights on the microscopic mechanism underlying the emergence of totally different ground states out of seemingly well-understood ingredients but also elucidate the intriguing interplay between topological aspects and strong correlations in condensed matter systems.
Special Research & Career Skills: Electron spectroscopic measurements including planar tunneling and point-contact spectroscopies; Thin film deposition techniques including sputtering and evaporation; Low temperature measurements; Data acquisition and analysis using LabVIEW and MATLAB; Efficient communication skills including conference presentations and paper publications; How to build collaborative relationships with other researchers; How to write successful proposals.