The Wisconsin MRSEC has created thin films of a fascinating magnetic material, Pr2Ir2O7, in which the magnetic moments are frustrated: No matter how they are arranged, some of the moments are always fighting to change their direction, like two bar magnets with their north poles shoved together. Frustration creates a rich landscape for discovery and manipulation of new magnetic effects and of electronic phenomena linked to magnetism.

When an electrically-insulating material is grown on top of another insulator, the interface between the two insulators can be populated by mobile electrons. This has been achieved in interfaces that have a polarization discontinuity, such as AlGaN/GaN and LaAlO3/SrTiO3. It would be valuable to create a layer of mobile positive charges called holes, because electronic devices rely on charge carried by both electrons and holes.

In a five-PI collaboration within NU-MRSEC IRG-1, photoinduced charge separation is probed between InSe and two organic molecular semiconductors using novel experimental techniques that combine laser illumination with conductive scanning probe microscopy. In addition to providing insight for mixed-dimensional InSe-organic van der Waals heterostructures, this work establishes a general experimental methodology for studying localized charge transfer at the molecular scale that is applicable to other photoactive nanoscale systems.

“Experimenta con PREM” is a summer high school program organized by PREM-UPR (Univ. of Puerto Rico [PR]) faculty. Led by Wallace and Licurse, Penn participates annually by creating workshops and staffing those workshops with LRSM post-docs and grad students. This year at Penn, our volunteer facilitators (grad students Genesis Quiles-Galarza and Adriana Santiago-Ruiz) designed a series of materials science focused experiments and demos for 29 high school students.

Researchers at the University of Pennsylvania and Swarthmore College developed new non-invasive methods to measure the mechanical properties of defects in liquid crystals using magnetic fields and advanced imaging. The study revealed that the line tension of twist disclinations ranges from 75 to 200 piconewtons and increases logarithmically with sample thickness, providing crucial quantitative data for testing theoretical models of these defects.

The Philadelphia Science Festival is an annual nine day celebration of science aimed to engage and excite kids of all ages. Each day there are multiple events building up to the Science Carnival, which was held on April 30th, 2016, and attracted approximately 55,000 attendees.

The d parameters are a convenient parametrization for surface-related, quantum corrections. We  establish  a  systematic  approach  to measure the d parameter dispersion of a general two-material interface.

Semiconductors with both magnetic and optoelectronic properties are relevant for novel spintronic devices. With the aim of discovering new magnetic semiconductors, NU-MRSEC IRG-2 performed synthesis investigations on mixed halide-chalcogenides, resulting in the discovery of the new compound BaFMn0.5Te.

Top: Designed DNA structures of varying charge density and flexibility. Bottom left: Coacervate droplets formed from 1 DNA structure. Bottom middle/right: Binary droplets formed from a model system with 2 DNA structures.

The UC Santa Barbara ran a fully remote REU program in Summer 2020, with 18 students working on primarily computational projects. 18 students participated from 8 different colleges and universities. In addition to research, students participated in weekly intern group meetings, and weekly Zoom career building workshops, including Tips on Talks, Figures for Presentations, Poster Making, Finding Positions in Industry, Graduate School Panel, and others. All students presented their results in a virtual Summer Intern Colloquium.