IEM Distinguished Lecturers Seminar: New material properties caused by hidden magnetoelectric order
![Thumbnail](http://memento.epfl.ch/image/24360/1440x810.jpg)
Event details
Date | 21.04.2023 |
Hour | 13:15 › 14:00 |
Speaker |
Prof. Nicola Spaldin, Department of Materials, ETH Zürich |
Location | Online |
Category | Conferences - Seminars |
Event Language | English |
The seminar will take place in ELA 2 and will be simultaneously broadcasted in the main auditorium in Neuchâtel Campus (MC A1 272).
Coffee and cookies will be served at 13:00 before the seminar, in front of the two auditoriums.
Abstract
Most magnetic materials, phenomena and devices are well described in terms of their constituent magnetic dipoles. There is mounting evidence, however, that higher-order magnetic multipoles can lead to intriguing magnetic behaviors, which are often attributed to "hidden order" since they are difficult to characterize with conventional probes. In this talk I will discuss the existence and relevance of the so-called magnetoelectric multipoles, which form the next-order term, after the magnetic dipole, in the multipolar expansion of the energy of a magnetization density in a magnetic field. First, I will describe how magnetoelectric multipoles underlie multiferroic behavior and in particular how they determine the magnetic response to applied electric fields. Then I will discuss signatures of hidden magnetoelectric multipolar order, how it can be unearthed using density functional calculations and possibilities for its direct measurement. Finally, I will show that the bulk magnetoelectric multipolization causes a magnetization at the surface of a sample, even in materials with no net magnetization in their bulk.
Bio
Nicola Spaldin is the Professor of Materials Theory at ETH Zurich. She is best known for her development of the class of materials known as multiferroics, which combine simultaneous ferromagnetism and ferroelectricity. She is a passionate science educator, coordinator of her department’s curriculum revision "The Materials Scientist 2030, Who is She?", and holder of the ETH Golden Owl Award for excellence in teaching. When not trying to make a room-temperature superconductor, she can be found playing her clarinet, or skiing or climbing in the Alps.
Coffee and cookies will be served at 13:00 before the seminar, in front of the two auditoriums.
Abstract
Most magnetic materials, phenomena and devices are well described in terms of their constituent magnetic dipoles. There is mounting evidence, however, that higher-order magnetic multipoles can lead to intriguing magnetic behaviors, which are often attributed to "hidden order" since they are difficult to characterize with conventional probes. In this talk I will discuss the existence and relevance of the so-called magnetoelectric multipoles, which form the next-order term, after the magnetic dipole, in the multipolar expansion of the energy of a magnetization density in a magnetic field. First, I will describe how magnetoelectric multipoles underlie multiferroic behavior and in particular how they determine the magnetic response to applied electric fields. Then I will discuss signatures of hidden magnetoelectric multipolar order, how it can be unearthed using density functional calculations and possibilities for its direct measurement. Finally, I will show that the bulk magnetoelectric multipolization causes a magnetization at the surface of a sample, even in materials with no net magnetization in their bulk.
Bio
Nicola Spaldin is the Professor of Materials Theory at ETH Zurich. She is best known for her development of the class of materials known as multiferroics, which combine simultaneous ferromagnetism and ferroelectricity. She is a passionate science educator, coordinator of her department’s curriculum revision "The Materials Scientist 2030, Who is She?", and holder of the ETH Golden Owl Award for excellence in teaching. When not trying to make a room-temperature superconductor, she can be found playing her clarinet, or skiing or climbing in the Alps.
Practical information
- General public
- Free