Controlled Synthesis and Characterization of Nanostructured Topological Crystals
Prof. Shixiong Zhang
Topological crystalline insulators (TCIs) are a novel class of quantum materials that have unique metallic states on their surfaces. Such materials are expected to have potential applications in several fields, including tunable electronics and spintronics. The REU students will perform bottom up synthesis of various types of TCI nanostructures and carry out nanoscale characterization of the physical properties. This project will provide students unique opportunities to participate in of condensed matter physics, materials science and nanotechnology.
Topological States of Matter
Prof. Babak Seradjeh
In the past decade, the theory and experimental promise of topologically ordered states has been greatly expanded beyond the paradigmatic quantum Hall effect, leading to the discovery of several families of two- and three-dimensional topological insulators and candidate topological superconductors. The electrons in these systems are inert in the bulk, yet cost vanishingly little energy to excite at the system boundaries or inside bulk defects. These topological "zero modes" are typically governed by the Dirac equation, leading to some spectacular properties, such as half-integer charge fractionalization, quantized magneto-electric effect, emergent magnetic monopoles, and nonlocal entanglement. In this project, you will investigate aspects of model topological insulators and superconductors by employing analytical and simple numerical methods using Mathematica or Matlab, or coding in C/C++/Fortran. The problems are designed to understand the fundamental principles governing the system, their connection to experiments, and potential applications and architectures for novel devices. You will become familiar with relevant experiments, will learn the underlying concepts and a selection of theoretical techniques, including exact diagonalization, field theoretic, variational and perturbative methods.
X-ray and Neutron Scattering Studies of Nano-confined Systems
Prof. Paul Sokol
Our work focuses on the study of the structure and dynamics of condensed matter systems under confinement at the nanoscale. Confinement in nanometer size pores or on surfaces can drastically affect the properties of confined systems ranging from classical solids to quantum liquids and can even lead to new phases not present in the bulk. We use neutron and x-ray scattering to probe the microscopic structure and dynamics of these confined systems. Students will have the opportunity to participate in experiments both at IU and at national laboratories such as NIST, Oak Ridge National Lab, and Argonne National Lab.
Students will study the behavior of waves confined within waveguide and photonic crystal structures. Experimental projects have involved designing and building the structure and using a microwave network analyzer to look for novel behavior of the confined microwaves. Prof. Carini has supervised two REU students and two more in combined experimental-theoretical collaborations with Profs. Londergan and Schaich. In theory projects, students will perform calculations for the analysis of resonances and current flows in waveguide geometries.
Small Angle Neutron Scattering (SANS) Studies of Nanostructured Materials
Prof. David Baxter
The presence of the LENS facility within the department offers a number of unique opportunities for undergraduate research on materials. Prof. Baxter has particular interest in the SANS technique which probes the mesoscopic structure of materials (length scales from 1 to 100 nm), and in studying hydrogenous materials that may be suitable for improved neutron moderators through neutron transmission experiments. With both techniques it is possible to introduce students to the fundamentals, collect data on several samples, and complete the analysis of suitable samples within a period of 5 to 8 weeks. Specific projects we envision pursuing with students supported by this grant include neutron transmission of materials that may be used in future very cold neutron (VCN). Publication of these data is eagerly anticipated by the VCN community as these data are needed for testing new simulation codes for future source design. SANS projects of interest include geological samples (clays and coals), bone, and nanoparticles ranging from virus capside surrounding magnetic nanoparticles to molecular-sized graphene sheets (produced by colleagues in Chemistry).