Physics PPFP Mentors

Dr. Vladimir DobrosavljevicDobrosavljevicVladimir.jpg

Title of Research: Theoretical Condensed Matter Physics

Description of Research Area: The subject of metal-insulator transitions came to a renewed focus in the twenty-five years, following the discovery of high temperature superconductivity, which triggered much activity in the study of” bad metals”. Many of the materials in this family consist of transition metal or even rare earth elements, corresponding to compounds which are essentially on the brink of magnetism. Here, conventional approaches proved of little help, but recent research has lead to a veritable avalanche of new and exciting ideas and techniques both on the experimental and the theoretical front. In the last twelve years, a systematic new approach to strong correlations has been developed, based on dynamical mean-field theory (DMFT) methods. Some of the subjects that we have introduced have, in the last few years, become topics of central interest and much activity. This is especially true for glassy phenomena that emerge in many electronic systems with disorder. Topics related to non-equilibrium quantum dynamics are subjects of several upcoming major international workshops and meetings.

Special Research & Career Skills: Condensed matter theory, analytical and computational methods, including DMFT, vibrational methods, Monte-Carlo simulations, etc.

Website Links: Maglab Profile; Dobrosavljevic Lab

Dr. Stephen HillScreen_Shot_2018_01_19_at_11.51.44_AM.png

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.

Website Links: Electron Magnetic Resonance Site;  Maglab ProfileMaglab Facility;  Physics Today Article

Dr. Eric Hsiao Hsiao.jpg

Title of Research: 

Astronomy and Astrophysics:

Finding the origins of Type Ia supernovae

Description of Research Area: 

In the late 1990s, observations of distant Type Ia supernovae as standard candles led to the discovery of the accelerating expansion of the Universe. Since the discovery, modern cosmology has been faced with a conundrum: is today’s Universe dominated by a mysterious “dark energy” or are we witnessing the breakdown of General Relativity on the largest scales? Understanding the underlying cause of cosmic acceleration ranks as one of the greatest outstanding problems in contemporary physics. And the efforts that led to this amazing and confounding discovery were awarded the 2011 Nobel Prize in Physics.

Type Ia supernovae remain the most direct probe of the expansion history of the Universe and the properties of dark energy. Despite its wide use in cosmological studies, the origins of Type Ia supernovae, their explosion mechanisms and progenitor systems, remain unknown. Thus, improving future dark energy experiments is not just a question of observing more objects; as any survey, no matter how large, will ultimately be limited by systematic errors. A dominant source of systematic errors comes from our lack of knowledge of the physical origins of these explosions. Different paths of creating the explosions would have different evolution of properties with cosmic time, which can mimic effects of dark energy. As the planning for the next generation dark energy experiment is currently underway, deciphering the origins of Type Ia supernovae is more pressing than ever.

The postdoc will make detailed multi-wavelength time-series observations of nearby Type Ia supernovae with resources available to US astronomers, as well as, our South American and European collaborators. These results will then be compared to computer simulations in order to determine the origins of the explosions, and to find methods to improve upon current cosmological analysis using Type Ia supernovae.

Special Research & Career Skills: The postdoc will receive training in astronomical observations and data reductions, with emphasis on the near-infrared and mid-infrared wavelengths. I will also provide guidance in publishing the results, as well as, writing telescope time, grant, and job applications.

Website Link: Profile Page; Google Scholar

Dr. Kevin Huffenbergerkh_200px_a.jpg

Title of Research: Theory and Data Analysis for Next-Generation Cosmic Microwave Background Observatories

Description of Research Area: 

My group’s research in physical cosmology examines the structure and properties of the Universe. We work mostly on the Cosmic Microwave Background (CMB), and also on topics like large-scale structure, the cosmic X-ray background, gravitational weak lensing, and extra-galactic radio sources. 

An early epoch of cosmic inflation imprints a distinct, but not yet observed, signal in the CMB polarization power spectrum, called “B-modes.” This prospective signal has inspired a huge experimental effort to target it in the coming decade. Although technically challenging, detection would provide a powerful confirmation of this inflationary picture, and open an exciting new window on the physics of the early Universe.

The group is part of the Atacama Cosmology Telescope collaboration, the Simons Observatory collaboration, and the collaboration preparing for the stage IV project CMB-S4.  The postdoc can contribute to efforts to:

  • improve algorithms for CMB map-making and filtering
  • simulate and study the statistics of polarization foreground contamination
  • study large scale structure in cross-correlation

Special Research & Career Skills: I will help the postdoc with the development of technical, analytical, and computational skills.  I will provide guidance on grant writing, time management, professional development, and science writing.  The group provides access to the Simons Observatory network of outside mentors at Universities and National Laboratories.

Website Links: Lab Site; Google Scholar

Dr. Laura Reinareina06.jpg

Title of Research: Theoretical High-Energy Physics and Collider Physics

Description of Research Area: 

The research activity of my group mainly focuses on theoretical predictions for precision collider physics, to be used to disentangle both indirect and direct evidence of new physics beyond the Standard Model from measurements at the Large Hadron Collider.

In this context, we are particularly pursuing the study of anomalies in Higgs-boson couplings to Standard Model particles. Our program is twofold.

On one hand, we aim at providing state-of-the-art calculations of Standard-Model processes that represent irreducible backgrounds to Standard-Model Higgs-boson production. Processes like the production of electroweak (EW) vector bosons with heavy jets, or the production of top-quark pairs with bottom-quark pairs are very difficult to constrain and represent the main systematic uncertainty for current experimental measurements. We aim at providing more accurate theoretical predictions for these processes by considering both QCD and EW corrections and their effects in the evolution from production to detection energies. We have a long experience of higher-order QCD and EW calculation and we have recently developed an automatized framework (NLOX) to perform them. We would like to continue developing this framework, to develop the interface with parton-shower generators, and to specifically use it in the study of the aforementioned background processes.  On the other hand, we would like to explore the problem of constraining new physics interactions by studying their effects on EW and Higgs-boson precision observables using an Effective Field Theory (EFT) approach. As part of the HEPfit collaboration, we have recently studied the effect of combining Higgs-boson measurements and precision EW measurements to constrain the form of new physics interactions. We look forward to continuing and developing these studies using the wealth of data coming from Run 2 of the LHC and to extend them to the reach of the High-Luminosity LHC.

Special Research & Career Skills: Postdocs in our group interact daily with faculty and students, developing collaboration and mentoring skills. They travel to conferences and other institutions to give talks and build professional connections. I will assure mentoring towards job application and grant proposal writing.

Website Links: Profile Page


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