MIT scientists and colleagues have developed a simple-to-use device that can transmit current through electronic devices more efficiently than is possible today. As a result, the new diode, a type of switch, can reduce the power used in high-end computers, a major problem that is expected to worsen. Although in the early stages of development, the diode works twice as well as similar diodes reported by others. It may even be an important part of emerging computing technology.
The work, which is reported in the July 13 online issue of Physical Review Letters, also appears in Physics Magazine. Philip Moll, director of the Max Planck Institute for Structure and Dynamics of Matter in Germany says, “This paper shows that the superconducting diode is a problem that has been completely solved by technology.
Moll was not involved in the work. “The beauty of [this] work is that [Moodera and colleagues] achieved a record without even trying [and] their construction is still far from the best.”
Jagadeesh Moodera, current project leader and principal investigator at MIT’s research department, says, “Our engineering of high-performance diodes that are robust and capable of operating across a wide range of temperatures in simple systems and can open doors for new technologies Physics.
Moodera is associated with the Materials Research Laboratory, the Francis Bitter Magnet Laboratory and the Plasma Science and Fusion Center (PSFC). The nanoscopic rectangular diode – about 1,000 times thinner than the diameter of a human hair – is easily scalable. Millions can be produced on a single silicon wafer. Facing unprecedented change
Diodes, devices that allow current to flow easily in one direction but not the other, are ubiquitous in computer systems. Today’s solid-state computers contain billions of diode-like devices called transistors. However, these devices can get very hot due to electrical resistance, requiring a lot of power to power the high-powered systems and data centers behind many modern technologies, including cloud computing. . According to a 2018 report in Nature, these systems could use nearly 20% of the world’s energy within ten years. So work with the nature of the great awesome is the article that shines on the physics of the word.
Of course, popular transport is not inadequate and resist some temperature), but are expensive than their cousins, which can get the strength and extreme heat. However, until now, other approaches to the problem have involved more complex physics.
“The effect we found is due [in part] to the widespread availability of resources that can be easily and straightforwardly accessed by corporate executives. It’s good in your face,” Moodera says.
According to Moll of the Max Planck Institute for Structure and Dynamics of Matter, “the work is an important counterpoint to the current fashion of combining active diodes [with] critical science, such as state working together. Although in fact the superconducting diode is the most common and widespread in classical materials, due to some broken examples.
Research is relatively good
In 2020, Moodera and his colleagues found evidence of a unique pair of particles known as Majorana fermions. These two aspects could lead to a new family of topological qubits, the building blocks of quantum computing. While thinking about ways to create more efficient diodes, the team realized that the hardware platform they developed for Majorana’s work could also be applied to the diode problem.
They were right. Using this platform as a whole, they developed a series of diodes, each more efficient than the last. The first, for example, has a small nanoscopic layer of vanadium, a superconductor, made in the form commonly used in electronics (Hall bars). When they applied a small magnetic field similar to the Earth’s magnetic field, they observed the diode effect – the main polarity basis for current flow.
They then made another diode, this time containing a ferromagnetic superconductor (a ferromagnetic coating in their case), which creates a small magnetic field of its own. After applying a small magnetic field to magnetize the ferromagnet to create its own field, they found a larger diode effect that was stable even when the original magnetic field was turned off.
Features everywhere
The team went on to find out what was going on.
In addition to transferring current without resistance, superconductors also have other less well-known but ubiquitous properties. For example, they don’t like magnetic fields to go inside. When exposed to a small magnetic field, superconductors develop an internal structure that causes its own magnetic field to cancel out the external field, thus maintaining their unique state.
This phenomenon, known as the Meissner effect, can be thought of as our immune system producing antibodies to fight bacteria and other viruses. However, this works to a certain extent. Similarly, superconductors cannot completely block large magnetic fields.
The diodes the team developed use the universal Meissner screen effect. The small magnetic field they put in, either directly or through an adjacent ferromagnetic layer, allows the current storage system to repel the external magnetic field and continue to work efficiently.
The team also found that another key factor that makes these diodes superior is the small gap between the two sides or sides of the diode device. These differences “create a kind of asymmetry in the way the magnetic field penetrates the core,” says Moodera.
By designing the shape of their diodes to optimize for these differences – for example, one side has a jagged feature, while the other side is deliberately modified – the team found that they could increase efficiency from 20% to n up 50%. The research paves the way for devices whose components can be “tuned” for even higher performance, Moodera said.
In summary, the team found that surface asymmetries in superconducting diodes, the ubiquitous Meissner effect found in all conductors, and a third property known to conductors as vortex pinning all came together to create a diode effect. “It’s fun to see how sad it and partner francis is sad in sparc.” What’s the most exciting process] provides a simple system to improve performance. ”
Christoph problem is a professor at the University of Zegensburg in Germany. According to Strunk, who was not involved in the research, “the current work shows that it is amazing that a group of violent people can become non-reversible. Also , when combined with a ferromagnetic insulator, the diode effect can be maintained without an external magnet.
The direction of repair can be controlled by the magnetic remanence of the magnetic layer, which may have great potential for future applications. The work is important and beautiful both from the basic analysis and from the application.
Teenage donors
Moodera said the two researchers developed a piece of technology that did this while still in high school during a summer at Moodera’s lab. They are Ourania Glezakou-Elbert of Richland, Washington, who will attend Princeton this fall, and Amit Varambaly of Vestavia Hills, Alabama, who will enter the California Institute of Technology.
Varambaly says, “I didn’t know what to expect when I set foot in Boston last summer, but I certainly didn’t expect [to be] a co-author of a Physical Review article.
“Every day is exciting, whether I read a lot of articles to understand more about the diode display, or drive a machine to make a new diode to study, or hold discussions with Ourania, Dr .Hou and Dr. Moodera entered our research.
“I am deeply grateful to Dr. Moodera and Dr. Hou for giving me the opportunity to work on such an interesting project, and to Ourania for being a good researcher and friend.”
Source: MIT Materials Research Laboratory
