Abstract

Superconductors are probably sexier; semiconductors more practical. What is the appeal of insulating materials? Firstly, most magnets are insulating. Secondly, all ferroelectrics are insulating (ferroelectrics switch the direction of their electric polarization in an electric field in analogy to ferromagnets in a magnetic field). And some rather rare insulators are both magnetic and ferroelectric (multiferroic), which gives rise to some new effects, such as condensers that change their capacitance by 5,000% in a magnetic field or computer memories with three-state logic rather than binary. Paradoxically Gilbert showed in 1600 here in the east of England that magnetism and static electric effects are unrelated physical phenomena; I’ll try to show that this isn’t true. In addition, in nano-structures most insulators are actually semiconducting (if you make something thin enough, it always conducts), and how they conduct can be very interesting. In this talk I will discuss nanostructures and multiferroics.