Swirling cyclones of magnetism at the sub-micron scale that can trouble superconducting devices have been tamed by RIKEN scientists. Their technique could help to minimize magnetic noise in sensitive superconducting detectors, and could even help to build a new generation of devices for supercomputers.
When cooled below a critical temperature, superconductors carry electricity with no resistance. But magnetic fields can disrupt this behavior by introducing magnetic flux quanta into the material. These quanta, also known as vortices, are the basic units of magnetism, just as the charge of an electron is the fundamental unit of electricity.
Scientists can control how these vortices move by introducing tiny traps, or nano-holes, into the structure of the superconducting material. But since the pattern of these tiny traps is fixed once the device is made, it’s a relatively inflexible approach that restricts the way the vortices can be moved around.
Now, a team including Franco Nori and Sergey Savel’ev of RIKEN’s Frontier Research System in Wako, have shown how to precisely control the movement of magnetic flux quanta with an alternating electric current (AC)1.
The scientists tested the method on a high-temperature superconductor made from bismuth, strontium, calcium and copper (Bi2Sr2CaCu2O8 + ä). When the electrical current oscillates back and forth, the vortices obediently follow their rhythm.
Nori, also based at University of Michigan, US, says that the technique is like leading the magnetic flux quanta through a series of dance steps (Fig. 1). “The applied current acts as the leading dance partner and the vortices follow the steps imposed by the current,” he says.
More complicated rhythms are created by adding more overlapping alternating currents, allowing the scientists to steer their magnetic flux quanta through the material. “The two ‘control knobs’ we use are the ratio of the AC frequencies, and the relative phase difference between them,” explains Nori.
Savel’ev, also at Loughborough University, UK, adds: “By slowly varying either one of these two control knobs, vortices are pushed either in one direction or the opposite.”
Nori says that the technique could also be used to manipulate trapped ions, moving electrons around in certain types of crystal, or even separating different types of very tiny particles.
In the longer term, the scientists hope that the technique could contribute to the burgeoning field of ‘fluxtronics’—moving magnetic quanta around to manipulate computer data. This would potentially be much faster that conventional methods relying on shuttling electrons between transistors.
1. Ooi, S., Savel'ev, S., Gaifullin, M. B., Mochiku, T., Hirata, K. & Nori, F. Nonlinear nanodevices using magnetic flux quanta. Physical Review Letters 99, 207003 (2007).
Researchers at Fraunhofer monitor re-entry of Chinese space station Tiangong-1
21.03.2018 | Fraunhofer-Institut für Hochfrequenzphysik und Radartechnik FHR
Taming chaos: Calculating probability in complex systems
21.03.2018 | American Institute of Physics
An international team of researchers has discovered a new anti-cancer protein. The protein, called LHPP, prevents the uncontrolled proliferation of cancer cells in the liver. The researchers led by Prof. Michael N. Hall from the Biozentrum, University of Basel, report in “Nature” that LHPP can also serve as a biomarker for the diagnosis and prognosis of liver cancer.
The incidence of liver cancer, also known as hepatocellular carcinoma, is steadily increasing. In the last twenty years, the number of cases has almost doubled...
In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.
Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...
Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.
They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...
A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...
For the first time, an interdisciplinary team from the University of Basel has succeeded in integrating artificial organelles into the cells of live zebrafish embryos. This innovative approach using artificial organelles as cellular implants offers new potential in treating a range of diseases, as the authors report in an article published in Nature Communications.
In the cells of higher organisms, organelles such as the nucleus or mitochondria perform a range of complex functions necessary for life. In the networks of...
19.03.2018 | Event News
16.03.2018 | Event News
13.03.2018 | Event News
22.03.2018 | Trade Fair News
22.03.2018 | Earth Sciences
22.03.2018 | Earth Sciences