Probing the physics of complex oxide interfaces with scanning SQUID microscopy

Seminar
Speaker
Dr. Beena Kalisky, Department of Physics, Bar-Ilan University
Date
08/04/2013 - 13:30Add to Calendar 2013-04-08 13:30:00 2013-04-08 13:30:00 Probing the physics of complex oxide interfaces with scanning SQUID microscopy Complex oxide materials have a broad range of functionality such as ferromagnetism, piezoelectricity, and superconductivity. When combinations of complex oxides are grown as heterostructures, changes in the local electronic-structure at the interface can create new electronic phases that cannot exist in either parent material. One example is the interface formed by growing LAO on STO. Though both materials are insulators, the interface between them shows conductivity, superconductivity and even magnetism. In the LAO/STO system we discovered nanoscale patches of magnetism coexisting with superconductivity. An outstanding question is what controls the magnetism, and how it relates to the conductivity and superconductivity. I will describe our efforts to answer these questions, by mapping the landscape of ferromagnetism, superconductivity and conductivity with scanning SUQID microscopy. I will focus on our studies of current flow at the interface from a local point of view. We found that at low temperatures the current flows in highly conductive channels that are related to STO tetragonal domain structure. The interplay between substrate domains and the interface provides an additional mechanism for understanding and controlling the behaviors of heterostructures. Physics Department (Building 202), room 301 המחלקה לפיזיקה physics.dept@mail.biu.ac.il Asia/Jerusalem public
Place
Physics Department (Building 202), room 301
Abstract
Complex oxide materials have a broad range of functionality such as ferromagnetism, piezoelectricity, and superconductivity. When combinations of complex oxides are grown as heterostructures, changes in the local electronic-structure at the interface can create new electronic phases that cannot exist in either parent material. One example is the interface formed by growing LAO on STO. Though both materials are insulators, the interface between them shows conductivity, superconductivity and even magnetism.

In the LAO/STO system we discovered nanoscale patches of magnetism coexisting with superconductivity. An outstanding question is what controls the magnetism, and how it relates to the conductivity and superconductivity. I will describe our efforts to answer these questions, by mapping the landscape of ferromagnetism, superconductivity and conductivity with scanning SUQID microscopy. I will focus on our studies of current flow at the interface from a local point of view. We found that at low temperatures the current flows in highly conductive channels that are related to STO tetragonal domain structure. The interplay between substrate domains and the interface provides an additional mechanism for understanding and controlling the behaviors of heterostructures.

תאריך עדכון אחרון : 21/03/2013