Uncovering the connection between negative stiffness and magnetic domain walls

July 14, 2017, Carnegie Mellon University Materials Science and Engineering
Depiction of the internal magnetic structure of a domain wall and how it deforms with negative stiffness. Credit: Vincent Sokalski

Nature doesn't like having interfaces—this is why bubbles like to be round, and the surface of a pond settles to flat as long as it's not disturbed. These trends minimize the total amount of interface (or surface) that is present. As an exception to this behavior, certain materials are known to have a property, called negative stiffness, where the interface prefers to become distorted, or wavy, even without any external stimulation.

Interfaces with negative have been considered in crystals before, but the characteristic has now also been found in modern magnetism. Researchers in Carnegie Mellon University's College of Engineering have shown that the interface separating two oppositely magnetized regions of a material (called a wall) can also exhibit negative stiffness.

Materials Science and Engineering Ph.D. students Price Pellegren and Derek Lau, led by Assistant Research Professor of Materials Science & Engineering Vincent Sokalski, demonstrate that this stiffness is precisely what governs how the domain wall moves around in certain ultrathin magnets. In the study, they also describe how the domain wall can be adopted as a tool to measure the distribution of unwanted defects in the material.

This understanding of domain wall behavior is critical for the development of future energy-efficient computers where information is stored in the domain wall as it moves through a magnetic circuit.

Materials Science and Engineering Assistant Research Professor Vincent Sokalski explains his work on two-dimensional magnetic bubbles called skyrmions and their role in the search for new materials to improve the energy efficiency, speed, and reliability of computer memory and processors. Credit: Carnegie Mellon University College of Engineering

For more information on this research, please read the full article, "Dispersive Stiffness of Dzyaloshinskii Domain Walls," published in Physical Review Letters.

Explore further: A functional prototype nonvolatile ferroelectric domain wall memory

More information: Dispersive Stiffness of Dzyaloshinskii Domain Walls, Phys. Rev. Lett. 119, 027203 – Published 14 July 2017, journals.aps.org/prl/abstract/ … ysRevLett.119.027203

Related Stories

Manipulation of the characteristics of magnetic materials

November 17, 2016

Magnets are not everywhere equally magnetized, but automatically split up into smaller areas, so-called magnetic domains. The walls between the domains are of particular importance: they determine the magnetic properties ...

Magnetic fields at the crossroads

March 7, 2017

From compasses used in ancient overseas navigation to electrical motors, sensors, and actuators in cars, magnetic materials have been a mainstay throughout human history. In addition, almost all information that exists in ...

Recommended for you

Walking crystals may lead to new field of crystal robotics

February 23, 2018

Researchers have demonstrated that tiny micrometer-sized crystals—just barely visible to the human eye—can "walk" inchworm-style across the slide of a microscope. Other crystals are capable of different modes of locomotion ...

Researchers turn light upside down

February 23, 2018

Researchers from CIC nanoGUNE (San Sebastian, Spain) and collaborators have reported in Science the development of a so-called hyperbolic metasurface on which light propagates with completely reshaped wafefronts. This scientific ...

Recurrences in an isolated quantum many-body system

February 23, 2018

It is one of the most astonishing results of physics—when a complex system is left alone, it will return to its initial state with almost perfect precision. Gas particles, for example, chaotically swirling around in a container, ...

Seeing nanoscale details in mammalian cells

February 23, 2018

In 2014, W. E. Moerner, the Harry S. Mosher Professor of Chemistry at Stanford University, won the Nobel Prize in chemistry for co-developing a way of imaging shapes inside cells at very high resolution, called super-resolution ...

Hauling antiprotons around in a van

February 22, 2018

A team of researchers working on the antiProton Unstable Matter Annihilation (PUMA) project near CERN's particle laboratory, according to a report in Nature, plans to capture a billion antiprotons, put them in a shipping ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.