Spintronics | Graphene-Info

'Magic angle' trilayer graphene found to act as rare "spin-triplet" superconductor

Researchers at MIT and Harvard University have previously found that graphene can have exotic properties when situated at a 'magic angle'. Now, a new study by some of the members of the same team shows that this material could also be a "spin-triplet" superconductor – one that isn't affected by high magnetic fields – which potentially makes it even more useful.

"The value of this experiment is what it teaches us about fundamental superconductivity, about how materials can behave, so that with those lessons learned, we can try to design principles for other materials which would be easier to manufacture, that could perhaps give you better superconductivity," says physicist Pablo Jarillo-Herrero, from the Massachusetts Institute of Technology (MIT).

Read the full story Posted: Jul 22, 2021

“Bite” defects revealed in bottom-up graphene nanoribbons

Two recent studies by a collaborative team of scientists from two NCCR MARVEL labs have identified a new type of defect as the most common source of disorder in on-surface synthesized graphene nanoribbons (GNRs).

Combining scanning probe microscopy with first-principles calculations allowed the researchers to identify the atomic structure of these so-called "bite" defects and to investigate their effect on quantum electronic transport in two different types of graphene nanoribbon. They also established guidelines for minimizing the detrimental impact of these defects on electronic transport and proposed defective zigzag-edged nanoribbons as suitable platforms for certain applications in spintronics.

Read the full story Posted: May 19, 2021

Researchers design a graphene-based tunable beam splitter

Researchers from France, South Korea, and Japan have created a graphene-based “beam splitter” for electronic currents. The tunable device’s operation is directly comparable to that of an optical interferometer. The team believes that the technology could enable electron interferometry to be used in nanotechnology and quantum computing.
Quantum Hall valley splitter - schematic representation of the p − n junction. Image from article

An optical interferometer splits a beam of light in two, sending each beam along a different path before recombining the beams at a detector. The measured interference of the beams at the detector can be used to detect tiny differences in the lengths of the two paths. Recently, physicists have become interested in doing a similar thing with currents of electrons in solid-state devices, taking advantage of the fact that electrons behave similarly to waves in the quantum world.

Read the full story Posted: Apr 26, 2021

Researchers manage to induce “artificial magnetic texture” in graphene

An international research team, led by the University at Buffalo, has reported an advancement that could help give graphene magnetic properties. The researchers describe in their work how they paired a magnet with graphene, and induced what they describe as “artificial magnetic texture” in the nonmagnetic material.

Induced magnetism in graphene could also promote spintronics image The image shows eight electrodes around a 20-nanometer-thick magnet (white rectangle) and graphene (white dotted line). Credit: University at Buffalo.

“Independent of each other, graphene and spintronics each possess incredible potential to fundamentally change many aspects of business and society. But if you can blend the two together, the synergistic effects are likely to be something this world hasn’t yet seen,” says lead author Nargess Arabchigavkani, who performed the research as a PhD candidate at UB and is now a postdoctoral research associate at SUNY Polytechnic Institute.

Read the full story Posted: Feb 27, 2021

University of Washington team finds that carefully constructed stacks of graphene can exhibit highly correlated electron properties

A research team led by the University of Washington recently reported that carefully constructed stacks of graphene can exhibit highly correlated electron properties. The team also found evidence that this type of collective behavior likely relates to the emergence of exotic magnetic states.

“We’ve created an experimental setup that allows us to manipulate electrons in the graphene layers in a number of exciting new ways,” said co-senior author Matthew Yankowitz, a UW assistant professor of physics and of materials science and engineering. Yankowitz led the team with co-senior author Xiaodong Xu, a UW professor of physics and of materials science and engineering.

Read the full story Posted: Oct 07, 2020