A new technique for imaging spin properties at the nanoscale, Scanned Spin‐Precession Microscopy, works by incorporating a scannable micromagnetic tip in conjunction with any of a variety of established spin detection tools—electrical or optical, and improves upon their limited or non‐existent imaging capabilities. The magnetic field gradient from the probe directly selects spins from certain regions of the sample for study.

The mechanical failure of amorphous systems is not well understood, but recent work by Liu and co-workers suggests that low-frequency vibrational modes are concentrated in localized regions, or “soft spots,” that are prone to rearrange. Yodh and Liu experimentally studied the nature of soft spots in crystalline and amorphous packings of colloidal spheres.  In crystals  [1], they found soft spots to be concentrated on topological defects such as grain boundaries and dislocations that are well known to serve as flow defects in crystals.

Semiconductor nanocrystals are sensitive to air and solvents, which hinders wet-chemical processing under ambient conditions. This problem has limited the scaling of nanocrystal device dimensions and large-scale device integration achievable by  conventional processing. We demonstrated a simple, in-situ recovery route using indium metal as a chemical agent which upon thermal activation is triggered to diffuse and repair the damage introduced by chemical and environmental exposure that degrade the electronic properties of semiconductor NC thin films and their devices.

The idealized picture of an interface between two elemental materials is simply an abrupt transition between planes containing two different types of atoms.

The LRSM has organized a free, four week summer program for local high school students interested in materials science and engineering since 1993. Typically 24-28 students, usually juniors but occasionally well qualified sophomores, are accepted. Students are drawn from schools in the Delaware Valley within easy commuting distance of the LRSM. The program consists of lectures on materials, a computer lab, experimental labs, and field trips to both industrial and Penn facilities.

‘Living Smectics’ are being studied by a Physics PhD student, Stephanie Majkut, with Andrea Liu helping in theory.

The LRSM topological insulator (TI) seed is investigating how the connectivity of electronic bands in momentum space can be used to topologically classify insulators and semimetals. The theory of topological band structures has been generalized beyond TIs to include topological semimetals, including Weyl semimetals, Dirac semimetals and other symmetry protected topological states.

In collaboration with the group of Scott Crooker at Los Alamos National Lab and Greg Haugstad of the CSE Characterization Facility, graduate student Palak Ambwani and faculty member Chris Leighton have recently reported a remarkable finding in the area of complex oxides.