Scientists have found evidence of foreign matter in candidate material for quantum computers

Using the latest technology, scientists working at the National High Magnetic Field Laboratory, headquartered at Florida State University, have found evidence for quantum spin liquid, which is promising as a building block for tomorrow’s quantum computers.

While studying the so-called electron spin in the compound ruthenium trichloride, the researchers found attractive behavior. Their findings, published in the journal Today Nature Physics , Show that the electron spins interact throughout the material, effectively reducing the radiation throughout. This type of behavior compatible with quantum spin fluids was found in ruthenium trichloride at high temperatures and in high magnetic fields.

Spin Liquids, first theorized in 1973, became a mystery. Although some materials have shown promising signs for the condition of this material, it is very challenging to confirm its existence definitively. However, it is of great interest because scientists believe that they can be used to design smart materials in various applications such as quantum computing.

This study provides strong support for the fact that ruthenium trichloride is a spin liquid, said Kim Modic, a physicist who works in the field of Magleb’s pulsation and is now an assistant professor at the Institute of Science and Technology, Austria.

“I think this paper provides a new perspective on ruthenium trichloride and demonstrates a new way to detect the signatures of spin liquids,” said Modic, lead author of the paper.

For decades, physicists have extensively studied the charge of an electron, which carries electricity, paving the way for advances in electronics, energy, and other fields. But electrons also have a property called spin. Scientists also want to take advantage of the spin aspect of electrons for technology, but the universal behavior of spin is not yet understood.

Simply put, spinning an electron on an axis, like the top, can be thought of as oriented in certain directions. In magnetic objects, these spins align in the same or opposite direction with one or the other. This behavior, known as the magnetic order, can be induced or suppressed by temperature or a magnetic field. Once the magnetic order is pressed, more bizarre states of matter can emerge, such as quantum spin fluid.

In search of spin liquid, the research team settled on ruthenium trichloride. Its honeycomb-like structure, showing the spin at each site, resembles a magnetic version of graphene, another hot topic in condensed matter physics.

Ruthenium is heavier than carbon, resulting in stronger interactions between spins, said Arcady Shechter, a physicist at Magleb, who co-authored the paper.

The team expected that those interactions would increase the magnetic frustration in the material. It’s a kind of “three company” scenario in which two spins join, leaving a third in a magnetic limbo, which thwarts the magnetic sequence. That frustration, the team speculated, could result in a spin liquid state. Their data ended up confirming their suspicions.

“It appears that, at low temperatures and under the applied magnetic field, ruthenium trichloride shows signs of the behavior we are looking for.” “Spins not only orient themselves depending on the arrangement of neighboring spins, but are dynamic, like moving water molecules – while maintaining some relationship between them.”

Moduke said the teams were able to draw conclusions through a new technology called the resonant torsion magnetometry, which accurately measures the behavior of electron spins in high magnetic fields and could lead to many other new insights about magnetic materials.

“We don’t have workaround techniques or analytical machinery to study the excitation of electron spin, as we do for charge systems,” Modic said. “Methods that exist usually require a large sample size, which may not be available. Our technology is very sensitive and works on small, fragile samples. This could be a game-changer for the research field.”

Modic worked with other co-authors of the paper, Meglab physicists Shekter and Ross MacDonald, to measure ruthenium trichloride in post magnetic fields, then developed the technique as a postdoctoral researcher.

Their technique involves taking ruthenium trichloride samples at the size of the hair strand on the cantilever. They reintroduced quartz tuning forks just like a quartz crystal clock to vibrate the cantilever in a magnetic field. Instead of using it to tell the time accurately, they measured the frequency of vibration to study the interaction between ruthenium trichloride and the spin in the applied magnetic field. They presented their dimensions in two powerful magnets at the National Magleb.

“The beauty of our approach is that it is a relatively simple setup, which has allowed us to run our parameters in both 35-Tesla resistive magnets and 65-Tesla pulsed field magnets.”

The next step in the research is to study the system in Magleb’s world-record 100-Tesla Pulse Magnet.

“That high surface area of ​​the magnetic field should allow us to observe directly the suppression of the spin liquid state, which will help us to learn more about the internal functioning of this compound.”