Work has potential uses Quantum computing, And introduce a new way to uncover the secrets of superconductivity.
MIT Physicists and colleagues have demonstrated exotic forms of superconductivity in a new material that the team synthesized just about a year ago. Predicted in the 1960s, so far this type of superconductivity has proven difficult to stabilize. In addition, scientists have discovered that the same material can be manipulated to exhibit yet another, similarly exotic form of superconductivity.
The work was reported in the November 3, 2021 issue of the Journal. Nature..
Demonstration of finite momentum superconductivity in layered crystals known as natural superlattices means that the material can be fine-tuned to create different patterns of superconductivity within the same sample. And that, in turn, can affect quantum computing and more.
This material is also expected to be an important tool for unraveling the secrets of unconventional superconductors. This may be useful for new quantum technologies. Designing such a technique is difficult. One of the reasons is that it can be difficult to study the materials from which they are made. New materials, among other things, are relatively easy to create and may simplify such studies.
“The key theme of our research is that new physics is born from new materials,” said Joseph Scheckelski, Principal Investigator and Associate Professor of Career Development, Mitsui. “Last year’s first report was about this new material. This new work reports new physics.”
Checkelsky’s co-authors for the current paper include lead author Aravind Devarakonda PhD’21. Columbia University.. This work was a central part of Debarakonda’s dissertation. The co-author is Takehito Suzuki, a former researcher at MIT at Toho University in Japan. Shiang Fang, a postdoc of the MIT Faculty of Physics; Junbo Zhu, a graduate student of physics at the Massachusetts Institute of Technology; David Graph of the National Institute of High Magnetic Fields; Markus Kriener, MIT Associate Professor of Physics LiangFu; Efthimios Kaxiras at Harvard University.
New quantum material
Classical physics can be used to explain many of the underlying phenomena of our world until things get very small. Elementary particles such as electrons and quarks behave differently in ways that are not yet fully understood. Enter quantum mechanics, an area that seeks to explain their behavior and the resulting effects.
Checkelsky et al. Discovered new quantum materials, or those that exhibit the exotic properties of quantum mechanics on a macroscopic scale. In this case, the material in question is the superconductor.
Checkelsky explains that very recently there has been a boom in the realization of special superconductors that are two-dimensional or just a few atomic layers thick. These new ultrathin superconductors are partly interesting because they are expected to give insight into the superconductivity itself.
But there are challenges. For one thing, materials with a thickness of only a few atomic layers are so delicate that it is difficult to study on their own. Is there another approach to plumbing their secrets?
The new material created by Checkelsky and his colleagues can be thought of as equivalent to superconductivity. Layer cakeHere, one layer is an ultra-thin film of superconducting material, and the next layer is an ultra-thin spacer layer that protects it. Stacking these layers produces large crystals (which occur naturally when the constituent elements of sulfur, niobium, and barium are heated together). “And the macroscopic crystals I can hold in my hand behave like 2D superconductors. I was very surprised,” says Checkelsky.
Many of the probes that scientists use to study 2D superconductors are difficult to use in atomically thin materials. The new material is so big that “there are many more tools now. [to characterize it]”Checkelsky says. In fact, in the studies reported in the current paper, scientists used techniques that required large samples.
Superconductors carry electric charges in a special way. Instead of going through one electron, the charge is carried by two bound electrons in what is called a Cooper pair. However, not all superconductors are the same. Some anomalous forms of superconductivity can only appear if the Cooper pair can move unimpeded within the material over a relatively long distance. The longer the distance, the “cleaner” the material.
The material of the Checkelsky team is very clean. As a result, physicists were excited to see if it could exhibit anomalous superconducting states. In the current paper, the team shows that their new material is a finite momentum superconductor when a magnetic field is applied. This particular type of superconductivity, proposed in the 1960s, remains attractive to scientists.
Superconductivity is usually destroyed by a moderate magnetic field, but finite momentum superconductors can be further sustained by forming a regular pattern of regions with and without Cooper pairs. It has been found that this type of superconductor can be manipulated to form various anomalous patterns as Cooper pairs move between quantum mechanical orbitals known as Landau levels. In short, Checkelsky says scientists should be able to create different patterns of superconductivity within the same material.
“This is an impressive experiment that can demonstrate a Cooper pair moving between Landau levels of a superconductor. This is something that has never been observed before. Frankly, I got it. It’s very exciting because I never expected to see it in a crystal that I could have. To observe this elusive effect, the authors have boned against a unique two-dimensional superconductor previously discovered. Kyle Shen, a professor of physics at the University of Cornell, had to make breakthrough, high-precision measurements. It’s an amazing achievement not only in technical difficulty, but also in its ingenuity. ” increase. Shen was not involved in the study.
In addition, physicists have noticed that their materials also have yet another exotic type of superconducting component. Topological superconductivity involves the transfer of charge along edges or boundaries. In this case, the charge can move along the edges of each internal superconducting pattern.
The Checkelsky team is currently working to see if their materials can actually accommodate topological superconductivity. If so, “Can both new types of superconductivity be combined? What can it bring?” Checkelsky asks.
“It was a lot of fun to realize this new material,” he concludes. “There were a lot of surprises as we delved into understanding what it could do. It’s really exciting when we come up with something unexpected.”
Reference: A. Devarakonda, T. Suzuki, S. Fang, J. Zhu, D. Graf, M. Kriener, L. Fu, E. Kaxiras, JG Checkelsky, “Signs of Boson Landau Levels in Limited Momentum Superconductors”, November 3, 2021 Nature..
DOI: 10.1038 / s41586-021-03915-3
This work was supported by the Gordon and Betty Moore Foundation, the Navy Research Department, the US Department of Energy (DOE) Science Department, the National Science Foundation (NSF), and the Ratgers Materials Theory Center.
The calculation was done at Harvard University. Other parts of the work were carried out at the National Institute of High Magnetic Fields supported by NSF, Florida, and the Department of Energy.
Exotic New Material Could Be Two Superconductors in One – With Serious Quantum Computing Applications Source link Exotic New Material Could Be Two Superconductors in One – With Serious Quantum Computing Applications