Past events

Superconducting Quantum Metamaterials - 25 November 2013

Professor Steven M. Anlage, University of Maryland.

For the third in our series of Zepler Institute International Lectures, it was a privilege to be joined by Steven M. Anlage, Professor of Physics and faculty affiliate of the Department of Electrical and Computer Engineering at the University of Maryland, College Park.

Abstract

We have prepared meta-atoms based on radio frequency superconducting quantum interference devices (RF SQUIDs) and examined their tunability with dc magnetic field, rf current, and temperature. RF SQUIDs are superconducting split ring resonators in which the usual capacitance is supplemented with a Josephson junction, which introduces strong nonlinearity in the rf properties.  We find excellent agreement between the data and a model which regards the Josephson junction as the resistively and capacitively-shunted junction. A magnetic field tunability of 80 THz/Gauss at 12 GHz is observed, a total tunability of 56% is achieved, and a unique electromagnetically-induced transparency feature at intermediate excitation powers is demonstrated for the first time. The speed of tunability may be limited only by the intrinsic RC time constant of the meta-atoms, and may be less than 1 nano-second.  An RF SQUID metamaterial is shown to have qualitatively the same behavior as a single RF SQUID with regards to DC flux and temperature tuning.  

Short biography

Steven M. Anlage is a Professor of Physics and faculty affiliate of the Department of Electrical and Computer Engineering at the University of Maryland, College Park.  He received his B.S. degree in Physics from Rensselaer Polytechnic Institute in 1982, and his M.S. and Ph.D. in Applied Physics from the California Institute of Technology in 1984 and 1988, respectively.  His graduate work concerned the physics and materials properties of quasicrystals.  His post-doctoral work with the Beasley-Geballe-Kapitulnik group at Stanford University (1987 - 1990) concentrated on high frequency properties of high temperature superconductors.  In 1990 he was appointed Assistant Professor of Physics in the Center for Superconductivity Research at the University of Maryland, then (1997) Associate Professor, and finally (2002) Full Professor of Physics.  He was the interim Director of the Center for Nanophysics and Advanced Materials (2007-2009), and is a member of the Maryland NanoCenter.  In 2011 he was appointed a Research Professor at the DFG-Center for Functional Nanostructures at the Karlsruhe Institute of Technology in Germany. Read more.