Spin Wave Computing Power for Encryption and Quantum Computing

At a Glance

Researchers at Colorado State University in collaboration with Bryn Mawr College have developed novel systems and methods for encryption of non-volatile information storage using magnetic skyrmions. While skyrmions have received considerable attention as candidates for data storage, logic devices, and processing electronics, researchers discovered and experimentally demonstrated the ability to form skyrmions, deform the skyrmions, and then reform skyrmions with the same size and location as the origianls. Using this cycling process, information stored in skyrmions within thin magnetic films can be encryted and decrypted simply by changing a basic parameter, such as temperature.

Background

Magnetic skyrmions are small swirling magnetic quasiparticles with topological protection. Skyrmions may be observed in magnetic thin films withperpendicular magnetic anisotropy and strong anisotropic exchange interactions. They have unique spin textures with a well‐defined topological charge of +/‐ 1. Because of the skyrmion topology, transforming from a skyrmion to a uniform magnetic state, i.e., erasing the skyrmions, is difficult. Skyrmions can also be displaced by currents, and their inherent stability and easy of mobility makes them promising candidates for data‐storage solutions and other computing devices.

Skyrmion‐based data‐storage and logic applications usually require one or more of the following operations: creating/generating skyrmion, moving a skyrmion, switching, detecting a skyrmion, and erasing a skyrmion. Systems and methods to encrypt and decrypt information are of great interest generally and would be a desirable attribute of skyrmion‐based storage and logic devices. However, systems, mechanisms, and methods for such encryption using skyrmions have yet to be described.

Overview

The encryption concept is similar to that of disappearing ink, except in this case the information is written in magnetic layers in the form of skyrmions. The device is comprised of layers of different types of magnetic thin films. A skyrmion layer, such as an interface between cobalt and platinum films, is used to support the formation of magnetic skyrmions. A control layer, such as gadolinium is then used to control the encryption and decryption process. In a decrypted state, a round or oblong skyrmion is present and can be detected through photo-emission electron microscopy (PEEM), which can produce images of the spin distributions, or other techniques. To encrypt the data, you simply tune the magnetization and/or anisotropy of the control layer by changing a control parameter, such as temperature. The skyrmion will deform and distort, obscuring the skyrmions. If the control parameter is reversed, the skyrmion will reform.

Figure 1 contains experimental data that illustrate how a skyrmion can be obscured and then recovered by adjusting a control parameter, in this case temperature. The skyrmion is clearly visible in PEEM images at temperatures above 55K. As the temperature is decreased, the out-of-plane spinning that makes up the skyrmion changes and at temperatures of 40K and below, the skyrmions are replaced by complex in-plane spinning. When the temperature is raised, the skyrmions reform in the same place and with almost the same shape and size.  

Once information is encoded as skyrmions, this method makes it very easy to encrypt and decrypt the data. This method can work with both ferromagnetic and antiferromagnetic exchange coupling and does not require hall resistance measurements or magnetic tunnel junction devices. The decrypted state is stable at room temperature, and can be developed using already existing infrastructure.  

Benefits

  • Simpler than other non-skyrmion encryption techniques
  • Much smaller scale than other technologies
  • Very robust
  • Compatible with other quantum computing efforts

Applications

  • Data storage
  • Encryption
  • Computing technologies
Last Updated: April 2022
Light waves
Opportunity

Available for Licensing
TRL: 4

IP Status

US Patent Pending

Inventors

Kristen S. Buchanan
Xuemei Cheng
Xiao Wang

Reference Number
2021-042
Licensing Manager

Aly Hoeher
Aly.Hoeher@colostate.edu
970-491-7100