Researchers Make Data Storage Breakthrough Using Antiferromagnets
(By Becky Bracken) With the use of quantum sensors, researchers have made a breakthrough on the road to creating a new data storage medium, one which cannot be accidentally overwritten by magnetic fields. The innovation is critical, since electric and magnetic fields are how qubits are excited, forming the very basis of quantum computing.
The researchers pulled it off using antiferromagnetic materials, which, unlike their ferromagnetic counterparts, materials like iron, don’t generate a magnetic field. The report added 90 percent of all magnetically ordered materials are antiferromagnets.
“We can alter the single crystal in such a way as to create two areas (domains) in which the antiferromagnetic order has different orientations,” Natascha Hedrich, lead author of the study said.
She, along with her international team coordinated by the Department of Physics and the Swiss Nanoscience Institute at University of Basel.
For this research, the team used a single crystal of chromium(III) oxide (Cr2O3), which they selected because the structure is nearly perfectly ordered a crystal lattice, making it a good candidate to manipulate and observe.
“Thanks to the high sensitivity and excellent resolution of our quantum sensors, we were able to experimentally demonstrate that the domain wall exhibits behavior similar to that of a soap bubble,” team researcher Professor Patrick Maletinsky explained.
The domain wall, Maletinsky added is elastic like a bubble of soap. The domain “soap bubble” is constantly trying to minimize surface energy, which is an accurate predictor of how the antiferromagnetic material behaves. Demonstrating the ability to use domain walls to manipulate the trajectory of antiferromagnetic material is the first step toward the development to non-magnetic storage medium.
“We show that a wide range of spin clusters with antiferromagnetic intracluster exchange interaction allows one to define a qubit,” the report said. “For these spin cluster qubits, initialization, quantum gate operation, and readout are possible using the same techniques as for single spins.”
The team was able to manipulate the crystal’s structure to create small, raised squares which would move the domain wall on demand. The domain wall could be moved around at-will using the heat from a localized laser, the researchers explained.
“Next, we plan to look at whether the domain walls can also be moved by means of electrical fields,” Maletinsky said. “This would make antiferromagnets suitable as a storage medium that is faster than conventional ferromagnetic systems, while consuming substantially less energy.”