New quantum state demonstrated in higher-order topological magnet breakthrough

Decoherence is a major hurdle in making quantum applications feasible. However, a new study reveals a solution to this problem. The study authors developed an artificial quantum material featuring topological quantum magnetism.

“Topological quantum excitations, such as those realized in the topological quantum magnet we now built, can feature substantial protection against decoherence,” Jose Lado, one of the study authors and an assistant professor at Aalto University in Finland, said. 

“Ultimately, the protection offered by these exotic excitations can help us overcome some of the most pressing challenges of currently available qubits,” Lado added. 

The science behind quantum magnets

Quantum magnets are special materials where the magnetic properties show strange quantum behaviors that you normally only see at the tiny, atomic level. 

For instance, in such materials, different magnetic states can exist at the same time, similar to how a qubit shows the superposition of states i.e. it can represent both 0 and 1 simultaneously.

Topological quantum magnets are advanced materials that exhibit quantum behavior. Additionally, the magnetic spins of their particles are arranged in a way that creates stable and robust topological states.

These topological states are resistant to any external disturbances. Additionally, the spins in these materials can be entangled. This means they are deeply connected on a quantum level, and therefore don’t easily lose their quantum properties.

However, “So far, experiments have mostly explored non-interacting topological states, and the realization of many-body topological phases in solid-state platforms with atomic resolution has remained challenging,” the study authors note. 

This is where the findings from the new study come into play.

Realizing topological quantum magnetism

The study authors developed an artificial quantum material using magnetic titanium and magnesium oxide substrate. They could engineer and manipulate atoms of this quantum material to give rise to new quantum states of matter.

To introduce topological excitements in the quantum material, the researchers poked the atoms with a sharp metal needle. This poking caused the atoms to excite and brought changes in their magnetic moment, resulting in “topological excitations with enhanced coherence.” 

This experiment transformed the artificial quantum material into topological quantum magnets resistant to disturbance in the external environment.

“Excitations in topological quantum magnets have wildly different properties than those found in conventional magnets and could allow us to create new physical phenomena that are beyond the capabilities of current quantum materials,” Lado said.

Hopefully, these results will play a big role in realizing our quantum goals.

The study is published in the journal Nature Nanotechnology.