Credit: Pixabay/CC0 public domainSince receiving a $25 Million grant in 2019 to establish the NSF Quantum Foundry, UC Santa Barbara researchers have been developing materials that enable quantum information-based technology for applications such as simulation, communication, and computing.It could have been done.Stephen Wilson, a UCSB materials professor and foundry director, and several co-authors published a paper in Nature Materials. The paper describes a new material that was developed at the Quantum Foundry. It is a candidate superconductora metal in which magnetic fields are expelled and electrical resistance disappears. This could prove useful for future quantum computation.Wilson's group published a paper in Physical Review Letters that described a new material called cesium vanadium-antimonide (CsV3 Sb 5). This article featured surprising characteristics such as self-organized patterning and superconducting states. Brenden R. Ortiz, Elings Postdoctoral Fellow, made the discovery. Wilson stated that these characteristics were shared by many related materials including RbV3 Sb 5, and KV3 Sb 5. The latter (a mixture potassium, vanadium, and antimony) is the subject of the most recent paper, "Discovery a unconventional chiral order in kagome supraconductor KV3 Sb 5".Wilson observed that materials in this group of compounds are predicted to have interesting charge density wave Physics. This means that their electrons will self-organize in a non-uniform manner across the metal sites within the compound. This self-organized patterning is what the current research focuses on.The network of vanadium ions within these materials forms a corner-sharing network made up of triangles, known as a Kagome Lattice. This network is responsible for the predicted charge density wave state. KV3 Sb 5 was found to be a rare metal made from kagome planes. It also has superconductivity. Researchers speculated that the material may contain tiny current loops that could create local magnetic fields due to its other properties.Materials scientists and physicists had predicted for a long time that a material could exist that exhibits a type charge density wave order that breaks the law of time reversal. Wilson explained that this means it has a magnetic moment or a field associated with it. You can see that the charge moves in a small loop on the kagome lattice. This loop acts as a current loop and will provide you with a magnetic field. This state would be an electronic state of matter, and it would have significant consequences for the underlying superconductivity.Wilson's group had the task of making the material and analyzing its bulk properties. To identify the signatures of such states, Wilson's Princeton team used high-resolution scanning Tunneling Microscopy (STM). This was despite not being proven to be true.STM is achieved by scanning a very sharp wire tip of metal over a surface. The surface can be imaged by bringing the tip very close to the surface. Researchers describe analyzing and seeing a pattern in the electronic charge that changes with the application of a magnetic field. This suggests that a charge density wave state creates its own magnetic fields by coupling with an external magnetic field.This is precisely the type of work that the Quantum Foundry was created. Wilson stated that the foundry's contributions are important. It has played an important role in the development of these materials. Foundry researchers discovered superconductivity and then discovered signatures that indicated they might have a charge density wave. The materials are now being studied around the world because they offer many aspects that are relevant to different communities.He said, "They are of interest to people in quantum info as potential topological superconductors." They are interesting to those who study topological metals and new physics. This is because they could host interesting correlation effects. These are electrons' interfacing with each other, which could be what leads to the formation of the charge density wave state. They are also of interest to those who study high-temperature superconductivity because they contain elements that link them to certain features in these materials, even though they superconduct at a low temperature.KV 3 Sb 5, if it turns out to actually be what it is believed to be, could be used to create a topological qubit for quantum information applications. Wilson stated that topological computers should be made of qubits whose performance can be enhanced by the symmetries. This would mean they won't decohere (decoherence in fleeting entangled quantum states is a major problem in quantum computing) and have a reduced need for conventional error correction.He said that there are only certain types of states that can be used as topological qubits, and a topological supraconductor would likely host one. These materials are very rare. Although this system might be interesting, it's not confirmed and it's difficult to verify whether it is. It is still a long way to go before we can fully understand this new class superconductors.Continue reading Team discovers surprising quantum behavior in the kagome lattice
