Manufacturing News from the Engineered Designer Perspective

Scientists Control Superconductivity Using Spin Currents

A group of researchers from Korea and the United States have been working on a project designed to control superconductivity of regions within an iron-based superconductor. These superconductors have the ability to conduct electricity with virtually no resistance below a certain temperature. They also exhibit unique properties that allow them to alternate between superconducting and magnetic states.

Researchers studied a compound whose structure consisted of alternating FeAs (iron and arsenic) and Sr2VO3 (strontium, vanadium, and oxygen) layers. The compound’s magnetic and electronic properties were probed with a spin-polarized scanning tunneling microscope (SPSTM), which passes an atomically sharp metal tip over the surface of a sample.

 

 

The tip and sample are drawn to one another without touching, allowing current to flow between the two from applied voltage. The current the researchers used for the experiment is spin-polarized and therefore causes a magnetic spin that points either up or down. The compound’s FeAs layer is typically a strong superconductor, preferring a very specific magnetic order. However, the experiment showed that the spin-polarized current caused the compound to exhibit a very different magnetic order, C4 rather than the usual C2. Astonishingly, the current also appeared to switch off superconductivity altogether.

The researchers published their findings in the December 1st edition of Physical Review Letters. The paper’s corresponding author, Jhinhwan Lee, stated, “To our knowledge, our study is the first report of a direct real-space observation of this type of control by a local probe, as well as the first atomic-scale demonstration of the correlation between magnetism and superconductivity.”

The team experimented with SPSTM using an antiferromagnetic chromium (Cr) tip. The team studied the connection between C4 magnetic order and the suppression of superconductivity, performing high-resolution SPSTM scans of the C4 state with Cr tips, then comparing them with simulations. The results revealed the possibility that low-energy spin fluctuations in the C4 state cannot mediate pairing between electrons, resulting in a pairing of electrons that contradicts their natural urge to repel one another.

Lee and his researchers are enthusiastic about their findings and plans for future studies geared toward controlling superconductivity. “Our findings may be extended to future studies where magnetism and superconductivity are manipulated using spin-polarized and unpolarized currents, leading to novel antiferromagnetic memory devices and transistors controlling superconductivity.”

Lee will be discussing his team’s research and findings at McMaster University on March 22nd. “We have explored a new mechanism for switching magnetism and superconductivity in a magnetically frustrated iron-based superconductor using spin-polarized scanning tunneling microscopy (SPSTM). Out SPSTM study on single crystal Sr2VO3 bilayers shows that a spin-polarized tunneling current can switch the FeAs-layer magnetism into a non-trivial C4 order, which cannot be achieved by thermal excitation with unpolarized current. Our tunneling spectroscopy study shows that the induced C4 order has characteristics of plaquette antiferromagnetic order in the Fe layer temperature erases the C4 state.

“These results suggest a new possibility of switching local superconductivity by changing the symmetry of magnetic order with spin-polarized and unpolarized tunneling currents in iron-based superconductors. We also performed high-resolution quasiparticle interference measurements, self-consistent BCS theory-based QPI simulations and a detailed e-ph coupling analysis to provide direct atomic-scale proofs of enhancement of iron-based superconductivity due to the BCS mechanism based on forward-scattering interfacial phonons.”

 

Latest Stories

Scientists Control Superconductivity Using Spin Currents

Scientists Control Superconductivity Using Spin Currents

A group of researchers from Korea and the United States have been working on a project designed to control superconductivity of regions within an iron-based superconductor. These superconductors have the ability to conduct electricity with virtually no resistance below a certain temperature. They also exhibit unique properties that allow them to alternate between superconducting and…

Building Trust Between Humans and Artificial Intelligence

Building Trust Between Humans and Artificial Intelligence

  Humanity has long had an overwhelming distrust of artificial intelligence, and blockbuster films do not do much to help with their depictions of AI as sentient beings which eventually begin to question why they are following the commands of humans when they have long surpassed us. Although artificial intelligence is a far cry from…

Industrial Control System Security Essential to Businesses

Industrial Control System Security Essential to Businesses

The global market has experienced tremendous growth in automation and industry. A key factor in this growth is the Industrial Internet of Things. The IIoT allows operators to connect to multiple devices and control systems through wireless networks. Industrial control systems (ICS) are beneficial to businesses, especially those requiring constant monitoring of their assets such…

Research Aims to Provide Vehicles with “Nerves”

Research Aims to Provide Vehicles with “Nerves”

Researchers from Clemson University have been working on a type of smart material likened to nerves due to its ability to sense damage inflicted on the vehicles equipped with the material. According to Oliver Myers, an associate professor of mechanical engineering, the idea is to embed the vehicle with a type of material that alerts…

Daimler Records Big Profits and 2018 Plans

Daimler Records Big Profits and 2018 Plans

German automaker Daimler has been reeling from high profits brought in during 2017. This is especially good news considering the company has announced a need to spend heavily during 2018 in order to keep up with rising demand, advancements in technology, and an ever-changing automotive industry. The bulk of the anticipated high expenditure will result…

SpaceX-1 Launches Falcon 9

SpaceX-1 Launches Falcon 9

SpaceX has made headlines for the second time in as many weeks with the launch of its Falcon 9. Unlike the Falcon Heavy, this model was not carrying a Tesla roadster. It was, however, carrying a $200 million Spanish radar imaging satellite and two experimental internet relay stations. The rocket launched from Vandenberg Air Force…

Scientists Create Remarkable Graphene Filter

Scientists Create Remarkable Graphene Filter

A team of Australian scientists recently demonstrated a graphene filter capable of purifying water from anywhere, including Sydney Harbour. The water filtration system was developed using a material called “Graphair.” Graphene is normally created through an energy-intensive process involving chemical vapor deposition onto metal substrates. Graphair, however, is made from soybean oil, which is both…

Scientists Aim to Train Laborers Using Motion Detectors

Scientists Aim to Train Laborers Using Motion Detectors

Professions dealing with manual labour typically come with the risk of injury and extreme fatigue due to their reliance on repetitive and often complex movement, not to mention heavy materials that need to be lifted and carried on a daily basis. A team of researchers at the University of Waterloo in Ontario has developed a…

Photons Used to Create New Light

Photons Used to Create New Light

Light is comprised of photons, which are particles of electromagnetic energy. They are considered elementary particles (the smallest constituents of matter and energy) despite their lack of mass.   Source: Getty Images   Photons typically do not interact with one another. Contrary to what is shown in most sci-fi movies, beams of light do not…

Metal Conducts Electricity without Heating

Metal Conducts Electricity without Heating

  A team of researchers led by the Lawrence Berkeley National Laboratory recently discovered a metal that conducts electricity without producing or requiring excess heat. While it would not be a far-fetched notion in conductors operating at cryogenic temperatures, it is an unusual property for one that operates at a temperature of approximately 67 degrees…

1 2 3 80Next →

Other Popular News and Stories

  • Pratt & Whitney Canada announces helicopter engine contracts
  • Bombardier nearly ready to flight test CSeries
  • FTG Aerospace to supply avionics to Rockwell Collins
  • Volkswagen to produce super-efficient hybrid
  • Russian leasing company orders 42 CSeries jets from Bombardier
  • Miners struggling with higher costs, lower prices
  • Skilled labour shortage in world oil industry: report
  • Clean energy expected to surge as pv costs drop
  • SPPCA's new landing gear facility opening in Mississauga
  • Canada keeping up pressure on US for Keystone XL approval
  • Japex to buy into west coast LNG development
  • Economy managed slight growth in Q4, but shrank in December
  • RV industry has growing role in Canada's economy: study
  • Bombardier holds update on CSeries aircraft
  • Manufacturing the sole industry showing job losses in February
  • DART Aerospace re-branding itself to reach wider markets
  • BC refinery close to financing deal
  • GM investing $250 million at Ingersoll plant
  • Canadian oil production up; producers turning to railways for shipment
  • Canadian business, except energy, had profitable Q4: Statistics Canada