So, physicists have found a new quantum state of matter – a topological semimetallic phase – in an alloy of cerium, ruthenium and tin, and they did this at really low temperatures. Before, people thought you couldn’t get quantum criticality and topological properties in a single material. This could lead to a new type of material for quantum computing and high-efficiency electronics. You can find the research in Nature Physics.
The discovery of a new quantum state of matter could be a real game-changer. It could help develop quantum computing, make electronics more efficient, and improve sensing and imaging techniques. ScienceAlert says the research was published in Nature Physics.
The new quantum state, called a topological semimetallic phase, had been predicted earlier. It could turn up at really low temps in a material made of cerium, ruthenium and tin (CeRu4Sn6). Now, physicists have confirmed this.
At very low temperatures, CeRu4Sn6 reaches quantum criticality, i.e. the point at which the material is in a state of equilibrium between changes in its phase, when conditions are so cold that quantum fluctuations dominate, effectively transforming the material into a pool of waves rather than a mist of particles.
The surprising bit of the study is that quantum criticality can lead to states that were thought to be determined by interactions between particles, such as the behaviour of electrons as separate charge carriers.
So, according to physicists, the study shows that strong quantum effects can actually combine to create something totally new, which could help shape the future of quantum physics.
In physics, topology is all about the geometry of material structures. Some topological states can protect the properties of particles, which is different from how neighbouring particles can collide and disrupt each other’s behaviour. To get your head around topological states, you usually have to combine properties into particle maps, which is thought to be impossible in quantum critical conditions.
Quantum criticality and topology are both useful in materials, but for different reasons. Combining them might create a new type of material that’s really sensitive to quantum effects and really stable.
When physicists chilled CeRu4Sn6 to almost absolute zero and used an electric charge, they saw something called the Hall effect in the electrons carrying current through the material. So, the current is bending to the side.
The scientists said this was a clear sign of topological effects. The Hall effect normally needs a magnetic field to deflect electrons, but in this case there wasn’t. Instead, the path of the current was shaped by something in the material itself.
So, physicists found that where the material was most unstable in terms of its electronic structures, the topological effect was strongest. So, quantum critical oscillations actually stabilised the phase of matter that was detected.
Now, the researchers want to find out if this quantum state can be detected in other materials to see how common it is.