BGU Physics Department

Colloquium, Nov. 22nd, 2012

Oxide interfaces , perspectives for new physics and devices

Jack Harris Departments of Physics and Applied Physics, Yale University

One of the most remarkable predictions of the quantum theory of electronic circuits is that a small loop of resistive metal can have a perpetual current flowing in it in the absence of any voltage. This "persistent" current is directly analogous to the motion of electrons around the nucleus of an atom. The prediction that it could be observed in real electrical circuits generated considerable excitement... 25 years ago. Since then, experiments in this area have produced confusing results at odds with theory and even with each other. We have addressed this long-standing controversy by developing a new type of detector for persistent currents which offers much greater sensitivity and a less-invasive measurement than was previously possible. Our results have made possible a detailed comparison between experiment and theory. I will describe these results, which seem to give the clearest picture yet of persistent currents in resistive metals. I will also describe how persistent currents can now be applied to resolve outher outstanding questions in many-body condensed matter physics.