Graphene—a one-atom-thick sheet of carbon arranged in a honeycomb pattern—has long been celebrated as a wonder material.
It is stronger than steel, incredibly flexible, and an excellent conductor of electricity.
Despite holding the world record for electron mobility at room temperature, graphene has always fallen short of the best traditional semiconductors, such as gallium arsenide (GaAs), when tested at very low temperatures.
The main culprit has been electronic disorder caused by charged impurities in surrounding materials, which disrupt the flow of electrons.
Now, two independent teams of researchers, one at the National University of Singapore (NUS) and the other at The University of Manchester, have developed new methods to overcome this barrier.
Their work has pushed graphene past GaAs in terms of electronic quality, achieving record-breaking electron mobility and opening the door to new possibilities for high-speed electronics and quantum technologies.
In the first study, published in Nature Communications on August 11, 2025, the NUS team led by Assistant Professor Alexey Berdyugin developed a technique to shield graphene from stray electric fields.
They stacked two graphene layers at large twist angles of 10 to 30 degrees, ensuring they did not interfere electronically. One of the layers was doped to act as a metallic screen, blocking the unwanted electric fields from impurities.
This approach reduced charge fluctuations to unprecedentedly low levels. The improvement was so dramatic that quantum effects usually requiring strong magnetic fields could be seen at just a few milli-Tesla, hundreds of times weaker than normal.
Transport mobility exceeded 20 million cm²/Vs, while quantum mobility surpassed even the best GaAs systems.
The second study, published in Nature on August 20, 2025, was led by Nobel Laureate Sir Andre Geim and Dr. Daniil Domaretskiy at The University of Manchester, in collaboration with Berdyugin.
Their approach placed graphene less than a nanometer away from a metallic graphite gate, separated only by an ultra-thin insulating layer of hexagonal boron nitride.
This close proximity created powerful Coulomb screening, suppressing disorder almost entirely. The result was Hall mobilities above 60 million cm²/Vs, the highest ever reported, with quantum Hall effects visible at magnetic fields as weak as Earth’s natural field.
Together, these two approaches provide complementary solutions to a long-standing problem in graphene research.
One method allows for tunable control using twisted graphene layers, while the other provides an ultra-pure graphene platform screened by graphite. Both approaches enable the study of delicate quantum phenomena that were previously inaccessible.
The breakthroughs have broad implications. They could accelerate progress in quantum metrology, which underpins global electrical standards, and advance next-generation electronics where speed and energy efficiency are crucial.
The researchers also believe these methods will provide powerful tools for exploring new states of matter in moiré quantum materials, with potential applications in quantum computing.
For graphene, long hailed as a miracle material, these results mark a turning point. As Ph.D. student Ian Babich from NUS put it, “The performance we can now achieve means there is a whole new space of physics to explore.”
Source: National University of Singapore.
