Colloquium: Professor Bill Atkinson, Department of Physics and Astronomy, Trent University

Ferroelectric Domain Walls as Reconfigurable Circuits

Ferroelectric materials are, with few exceptions, electrically insulating.  In 2009, it was shown that certain kinds of ferroelectric domain walls form conducting channels that can be manipulated by external electric fields.  There is now a widespread focus on using the domain walls as reconfigurable circuit elements.  Of special interest, several groups have demonstrated that domain walls have memristive properties—namely, their electrical resistance depends on their history.  This is a prerequisite for logic-in-memory computing, where the processing and memory elements are physically co-located.  Here, I will discuss recent theoretical work by our group showing that domain walls can have nontrivial spin-orbit degrees of freedom that may permit “spin-orbitronic” functionalities.  I will explain the simple physics underlying this statement and discuss, in broad terms, why this matters.