Researchers have developed a groundbreaking quantum state of matter, called a higher-order topological magnet, which could help solve major challenges in the realm of quantum technology.
When various quantum states merge, they can create new collective forms of matter. In the quantum world, when components like atoms that exhibit quantum properties come together, they can form large quantum states characterized by unique quantum excitations that are not found elsewhere.
A collaboration between Aalto University and the Institute of Physics CAS led to the creation of an artificial quantum material, constructed atom by atom using magnetic titanium layered on a magnesium oxide base. They meticulously controlled the interactions among the atoms within this material to create a novel quantum state of matter. Jose Lado from Aalto University formulated the theoretical framework for this topological quantum magnetism, while a team spearheaded by associate professor Kai Yang at the Institute of Physics CAS constructed and analyzed the material through precise atomic manipulation techniques using scanning tunneling microscopy.
This research marks the first demonstration of a new quantum state, termed a higher-order topological quantum magnet. This type of magnet could offer a promising approach to improve protection against decoherence in quantum applications.
The findings were published today in Nature Nanotechnology
In addition to its scientific significance, this type of topological quantum many-body matter, like the newly discovered quantum magnet, has the potential to revolutionize future quantum technologies.
‘The creation of a many-body topological quantum magnet opens up a thrilling new avenue in physics. The excitations in these topological quantum magnets exhibit vastly different characteristics compared to traditional magnets, potentially enabling the discovery of new physical phenomena that go beyond the limitations of existing quantum materials,’ Lado explains.
Quantum magnets are unique materials that achieve a quantum superposition of magnetic states, effectively translating quantum effects from the microscopic level to a macroscopic scale. They are home to unusual quantum excitations, including fractional excitations, in which electrons act as if they have been subdivided into multiple parts—something that can’t be found in other materials.
To control the behavior of the atoms within the assembled quantum material, the researchers employed a technique that involved probing each atom with a minute needle. This method allows for precise manipulation of qubits at the atomic scale. The needle, which is an atomically sharp metal tip, effectively stimulates the local magnetic moment of the atoms, leading to topological excitations that exhibit greater coherence.
‘Topological quantum excitations, such as those we have successfully created within this topological quantum magnet, provide significant resistance against decoherence. This protection can ultimately help us tackle some of the most significant challenges faced by current qubits,’ Lado notes.
During their experiments, the researchers found that the topological excitations were resilient against external disturbances, a behavior that matched predictions made based on Lado’s theoretical model. They also observed that the quantum coherence of these topological excitations exceeded that of their individual components. This discovery hints at a potential method for transforming their artificial quantum material into a fundamental building block for quantum information systems that are safeguarded against decoherence.
