The strange metal behavior of magnetoresistance of graphene breaks record high
Researchers from The University of Manchester have finally reported record-high magnetoresistance that appears in graphene under ambient conditions.
This according to a press release published on Wednesday by the institution.
A research team led by Professor Sir Andre Geim has found that good old graphene can reach a record-breaking above 100% in magnetic fields of standard permanent magnets (of about 1,000 Gauss).
“People working on graphene like myself always felt that this gold mine of physics should have been exhausted long ago. The material continuously proves us wrong finding yet another incarnation. Today I have to admit again that graphene is dead, long live graphene,” Geim said in a press statement.
The researchers used high-quality graphene and tuned it to its intrinsic, virgin state where there were only charge carriers excited by temperature, creating a plasma of fast-moving “Dirac fermions.”
“Over the last 10 years, electronic quality of graphene devices has improved dramatically, and everyone seems to focus on finding new phenomena at low, liquid-helium temperatures, ignoring what happens under ambient conditions. This is perhaps not so surprising because the cooler your sample the more interesting its behavior usually becomes. We decided to turn the heat up and unexpectedly a whole wealth of unexpected phenomena turned up,” said Dr Alexey Berdyugin, the corresponding author of the paper.
The researchers have also found that, at elevated temperatures, neutral graphene becomes a so-called “strange metal,” the name given to materials where electron scattering becomes ultimately fast, being determined only by the Heisenberg uncertainty principle.
The phenomenon of linear magnetoresistance has puzzled scientists for more than a century since it was first observed. The current Manchester work provides important clues about the origins of the strange metal behavior and of the linear magnetoresistance. Perhaps, the mysteries can now be finally solved thanks to graphene as it represents a clean, well-characterized and relatively simple electronic system.
“Undoped high-quality graphene at room temperature offers an opportunity to explore an entirely new regime that in principle could be discovered even a decade ago but somehow was overlooked by everyone. We plan to study this strange-metal regime and, surely, more of interesting results, phenomena and applications will follow”, added Dr Leonid Ponomarenko, one of the leading paper authors.
Source: Interesting Engineering
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The strange metal behavior of magnetoresistance of graphene breaks record high