Conceptual image of a quantum computing magnetometer. (©Roalin -Stock.adobe.com)
Voltage-controlled “vortex” unlocks a new era of energy-efficient memory
In a nutshell, put it in a nutshell
Scientists have created “vortices” small, swirling magnetic structures controlled by voltage rather than electric currents. Unlike traditional magnetic memory, computer memory is potentially more energy efficient. Storage
Barcelona – Computers are hungry beasts. They devour huge amounts of power, especially when writing data to memory. This is a process that traditionally uses current to generate wasteful heat. But what if you could control magnetic information storage with voltage instead? This approach is gaining traction as researchers are looking for more energy-efficient computing solutions than data-hungry worlds.
In a paper published in Nature Communications, researchers from the Autonomous University of Barcelona published a new nanoscale magnetic state called “Vort” (short for magnetic ion ion vortex). This innovative approach can use the movement of voltage-controlled ions to create and manipulate magnetic patterns that swirl at the nanoscale, transforming the way computers store and process information.
“This is a nanoscale, unexplored object so far,” explains Jordi Sort, ICREA researcher and director of research at the UAB Physics Department, in a statement. “There is a great demand for controlling magnetic states at the nanoscale, but surprisingly, most of the magnetic ions research has so far focused on the study of membranes of continuous materials. Looking at the effects of ion displacement in discrete structures of nanometer dimensions, the analysed “nanodots” emerge, which are inherent in these types of structures. ”
A research team led by scientists at the University of Barcelona has discovered a way to accurately control the magnetic properties of small metal points with very low power consumption. These methods allow you to continuously adjust the magnetic switch to analog, just like turning the dimming switch, rather than flipping the binary on/off toggle.
The mechanism of the vortex
At the heart of this innovation is the clever manipulation of nitrogen ions in specially operated iron-cobalt nitrogen (Fecon) nanomagnets. By applying voltages, researchers can extract nitrogen ions from these small dots and convert them magnetically to active in a controlled, stepwise manner. This creates a unique, swirling magnetic pattern. This is a precisely adjustable and manipulated vortex.
“The ‘vortices’ we developed allow us to unprecedentedly control magnetic properties such as magnetization, forcing, detachment, anisotropy, or critical areas where vortices have formed or annihilated. These are the basic properties for storing information in magnetic memory. This has been made possible by a voltage activation process with very low energy consumption, allowing it to be controlled and adjusted in a reversible way in analogue.”
Unlike traditional magnetic vortices that are typically fixed to manufactured properties, these voltage controlled vortices offer unprecedented flexibility. Their magnetic strength, stability, and behavior can all be adjusted after manufacture, eliminating the need for energy-intensive technologies such as laser pulses and currents to manipulate magnetic states.
“Instead of using current, voltage operating procedures prevent heating on devices such as laptops, servers, and data centers, and significantly reduce energy losses,” adds Spasojević.
Brain computer connection
Traditional computing relies on binary states (zero and zero), but the human brain processes information in a much more subtle analog fashion with different connection strengths between neurons. This new technology brings us closer to brain-like computing by enabling analog states with a continuous degree of magnetization that can be adjusted by voltage, leading to more efficient and sophisticated computing architectures.
By controlling how long the voltage takes, researchers can accurately adjust the thickness of the ferromagnetic layer, allowing for transitions from different magnetic states to single domains to vortex states.
Researchers have shown that precisely controlling the thickness of the voltage-generating magnetic layer, the magnetic state of the material can be freely varied in a controlled, reversible way, between nonmagnetic states, states with uniform magnetic orientations (as seen in magnets), and new magnetic ion vortex states.
From Lab to Application
“We envision, for example, the integration of reconfigurable magnetic ion vortices in neural networks as dynamic synapses that can mimic biological synaptic behavior,” explains Sort.
In the brain, intersynaptic connections between neurons have different weights (intensities) that dynamically adapt to activity and learning processes. Similarly, “vortices” can provide tunable neuronal synaptic weights reflected in reconfigurable magnetization or anisotropy values for brain-inspired spintronic devices.
“The activity of biological neurons and synapses is also controlled by electrical signals and ions that are similar to magnetic ion units,” says Spasojević.
In current neural systems, one challenging aspect is creating and adjusting synaptic weights, that is, the strength of connections between artificial neurons. Vortex can perform this function, and magnetization intensity is controlled by voltage and can represent different connection strengths.
The energy efficiency of this approach is particularly noteworthy. Traditional methods for manipulating magnetic states often require substantial energy input via current or laser pulses. Vortex voltage-based control consumes minimal power and aligns with the urgent need to reduce the energy consumption of information technology as data processing demands continue to increase.
Researchers believe that in addition to its impact on brain-inspired devices, analog computing, or multi-state data storage systems, Vortions may have other potential applications, such as medical therapy technology, data security, magnetic spin computing devices, and spin wave generation.
In a world increasingly dominated by data-hungry technologies, from artificial intelligence to the Internet of Things, innovations that increase computational efficiency while reducing energy consumption has become more important than ever. Voltage-controlled vortexes can quickly join Arsenal, a technology that will help address these challenges, and swirl towards the future of computing with energy-efficient spins.
Paper overview
Methodology
Researchers used electron beam lithography to create experimental nanodots. This is a technique that uses a concentrated beam of electrons to draw custom shapes on special electron-sensitive materials. They applied photoresist materials that begin with silicon wafers coated with titanium and platinum layers, which change their properties when exposed to electron beams. After exposure and development, they deposited a 35-nanometer layer of iron cobalt nitrogen (Fecon) using a technique called magnetron sputtering. The resulting nanodots were 280 nanometers in diameter, 300 times thinner than human hair.
To study voltage-induced changes, these nanodots were placed in custom constructed electrochemical cells containing propylene carbonates containing sodium and hydroxide ions. They applied a voltage between the platinum layer beneath the nanodot and the counter electrode, creating an electric field that drives the nitrogen ions coming and going into the nanodot. Throughout this process, they measured magnetic properties using magneto-optical effect (MOKE) magnetometry, and detected changes in reflected light through magnetization.
result
This study revealed several important findings. Initially, the Fecon Nanodots did not show permanent magnetism. Applying a negative voltage (-25V) gradually moves nitrogen ions from the nanodots, creating a magnetic region. For short application times (approximately 6 min), the nanodots developed simple magnetic behavior, and the magnetization was oriented uniformly in one direction. With longer application times, the magnetic behavior changes dramatically, indicating a distinctive pattern of magnetic vortices.
The team discovered that it could precisely control magnetic properties, such as resistance to annihilation, the field where vortices form and disappear, and most importantly, the strength of the magnetization itself. This process turned out to be completely reversible. Applying a positive voltage (+25V) causes nitrogen to re-enter into the nanodots, gradually returning to its original nonmagnetic state.
Detailed imaging revealed that nitrogen migration creates clear boundaries within each nanodot and divides them into two different layers. It is a nitrogen-depleted magnetic layer at the bottom and a nitrogen-rich non-magnetic layer at the top.
limit
This research is groundbreaking, but there are some limitations to consider. Current demonstrations rely on liquid electrolytes and are not practical for commercial electronics that require solid solutions. The speed of nitrogen ions transfer requires significant improvements in practical computing applications that require rapid read/write operations.
As the experiments were conducted under laboratory conditions using specialized equipment, including synchrotron facilities, translated the findings into practical, mass-produced devices represents a critical engineering challenge. Additionally, the relatively high voltage (±25V) used must be reduced for integration with traditional electronics.
Funds and disclosure
This research was supported by the European Research Council through the 2021-ERC Advanced Reminder Grant and has additional funding from the generalitat de catalunya and the Spanish government. The researchers have used the facilities at several institutions, including the Alba Synchrotron Light Facility in Spain, the Istitoto Nagioneru Dirisel Cametrologica in Italy, and Colorado State University in the United States. The authors declared no competing interests related to this work. This study brought together an international team of researchers from Spain, Italy and the US, combining expertise in materials science, magnetism and advanced characterization techniques.
Publication information
The study entitled “Magneto-ion ion vortex: A swirling spin analog memory nanomagnet with voltage refitting” was published in Nature Communications on February 26, 2025 (Volume 16, Article No. 1990). The study was led by Professor ICREA of UAB Physics Jordi Sort and postdoctoral researchers of UAB Physics Irena Spasojevic as the first author of the publication. Other contributors include Zheng Ma of the UAB Physics, Aleix Barrera and Anna Palau of the Institute for Materials Science in Barcelona, and researchers at Istituto nazionale di ricerca metrogica (inrim), researchers at Turin, Italy, and Italdo State University. This article can be accessed under the Open Access Code through the Nature Communications website with the DOI identifier 10.1038/s41467-025-57321-8.
