Research
The qualitatively new behavior of materials at small length scales provides new vistas for engineering materials with exciting physical properties. As the size of the sample shrinks, conventional bulk thermodynamics becomes irrelevant and we enter the realm of mesoscopic physics. The equilibrium behavior of small systems is governed by the prevailing number of surface atoms that behave differently from the bulk ones. The electronic properties are also subject to reduced number of available electronic states. We take advantage of different scanning probe microscopy and spectroscopy techniques to elucidate the local electronic properties of materials that are relevant to solving energy problems.
Superconductivity
One hundred years after its discovery, superconductivity is one of the most studied topics in laboratories around the world, both for understanding its origin on fundamental side and for its numerous applications. Abrikosov vortices play an important role in these studies since their mobility is responsible for energy dissipation in superconducting devices and cables. In our laboratory we study the Abrikosov vortices in mesoscopic superconductors and hybrid superconductor/ferromagnet systems.
We are also interested in complex materials that exhibit competing order parameters such as magnetism, superconductivity, charge density waves... We synthesize single crystals and study the behavior of order parameters on several parameters including electronic doping.
Magnetism
Rapid proliferation of electronic gadgets brings many benefits to people around the world in terms of communication and entertainment. On the other hand, these devices account for a growing portion of the energy household consumption and overall world consumption of electricity. Increasing the energy efficiency of these devices could have a far greater and immediate impact than gradual switch to renewable energy sources. The advances in the area of spintronics are therefore very important. Here we focus on local spin distribution and spin dynamics in nanosize magnetic objects.
Energy conversion
Over the past decade, vast resources have been devoted to developing proton exchange membrane fuel cells that use hydrogen fuel and oxygen from the air to produce electricity, for example, for automotive power. The main challenge is the design of cheap and stable fuel cell catalysts for the oxygen reduction reaction. In collaboration with the research team at Argonne National Laboratory we study the activity of material surfaces and specific sites in electrochemical processes using scanning probe microscopy.
