Research Lab of Peter Schiffer

Novel magnetic materials and nanostructures are important technologically and also provide excellent model systems in which to explore new physics. Professor Schiffer’s research group studies these systems through a wide range of experimental techniques. Recent research in our group has focused on the study of frustrated magnetic nanostructures known as  ‘artificial spin ice’, composed of arrays of thousands of precisely arranged nanometer-scale magnets. 
 
Artificial spin ice systems are frustrated by design, in that no set of orientations of the magnetic poles can align the north and south poles of the magnets for every pair of neighboring magnets.  The advantage to studying these systems is that they are both designable and resolvable: i.e., we can control the array geometry, and we can also observe how individual elements of the arrays behave.  By choosing the right geometries, we can experimentally explore physical phenomena that are inaccessible in natural magnetic materials, and make close comparisons with theory.  The group studies both artificial spin ice systems and the material properties of relevant magnetic materials, employing magnetic force microscopy, photoemission electron microscopy, electronic transport, and bulk magnetization measurements in our experiments.

Recent publications and presentations

We have studied the temperature and magnetic field dependence of the total magnetic moment of large-area permalloy artificial square spin ice arrays. The temperature...
Applied magnetic fields are an important tuning parameter for artificial spin ice (ASI) systems, as they can drive phase transitions between different magnetic ground states...
Long-range ordering is typically associated with a decrease in entropy. Yet, it can also be driven by increasing entropy in certain special cases. Here we demonstrate that...