The onset of collective phenomena
Fascinating functionality of superconductivity and ferroics at the nanoscale
How do collective phenomena, such as superconductivity and ferroics behave at the nannoscle?
The research of functional materials at the nanoscale constitutes a unique platform for mutual enhancement of fundamental science and cutting-edge technologies.
The ‘collectiveness’ of such functional systems cannot be reduced to a set of two-body interactions as done in other physical systems, and therefore its theoretical understanding is complex. Nevertheless, the experimental research of these systems enjoys the collective response and is therefore highly important for the advance in understanding these fascinating phenomena. Moreover, the collective response to external excitations enhances the functionality of these materials that are therefore garnering also much technological interest.
More specifically, we explore two systems: 1) Superconductors and 2) Ferroics. In superconductors, the electrons attract each other instead of the usual repulsion, so that they are bound together in pairs, Cooper pairs. The formation of pairs by itself is not sufficient to support superconductivity. Rather, all of the Cooper pairs interact collectively and share a common quantum state at a macroscopic lengthscale. The ‘collectiveness’ begins where there are just enough Cooper pairs to allow this common interaction, or more accurately, to allow a global order parameter with well-defined amplitude and phase. Exhibiting quantum behavior at the macroscopic scale, superconductors are hence very attractive for quantum technologies, which we also develop.
Ferroelectricity also exhibit collective interactions of charged particles (ion), just as superconductors do. Hence, ferroic systems can also exist only beyond a certain size, in which there are sufficient ions to support a common behavior. This size is just at the border between one and a few domains, or where there are enough interacting elements to form a single domain.
Practically, the origin of these two systems–superconductivity and ferroelectricity–is deep at the fascinating world of the nanoscale. Therefore, the main scientific question that occupies me is: How do collective phenomena, such as superconductivity and ferroics behave at the nanosacle?
We specialize in developing and implementing experimental methods to study the collective behavior in these two functional systems at the nanoscale and even at the atomic scale. We are also continuously looking into using our scientific discoveries to facilitate novel nano and quantum technologies. Fortunately, such a scientific-technological transition is natural in the systems we explore, thanks to the enhanced functionality they exhibit that is based on the collective interactions.