Two strategies from researchers at NUS and The College of Manchester have pushed graphene past gallium arsenide, setting world data in electron mobility and unlocking quantum results at Earth-strength magnetic fields.
Researchers from the Nationwide College of Singapore (NUS) and The College of Manchester have achieved a milestone lengthy thought out of attain: graphene units with electron mobilities that not solely rival however surpass the perfect gallium arsenide (GaAs)-based semiconductors. The dual breakthroughs handle graphene’s decades-old problem of digital dysfunction, unlocking ultra-clean efficiency essential for next-generation quantum and high-speed electronics.
Graphene, a one-atom-thick carbon lattice, already holds the document for room-temperature electron mobility. But, at cryogenic temperatures, GaAs-based techniques have persistently outperformed it—because of years of refinement and fewer electron-scattering imperfections. The stumbling block has been cost fluctuations from surrounding supplies, which create “electron-hole puddles” that restrict graphene’s mobility.
Now, two complementary strategies reported this month redefine the taking part in discipline. Researchers developed a technique utilizing large-angle twisted bilayer graphene as an electrostatic defend. By twisting two graphene sheets 10°–30° aside, one could possibly be doped to display screen stray electrical fields whereas remaining electronically decoupled. This decreased cost inhomogeneity tenfold and enabled hallmark quantum results—like Landau quantization—at magnetic fields practically 100× weaker than earlier than. Transport mobilities exceeded 20 million cm²/Vs, surpassing GaAs benchmarks.
A Manchester-led workforce headed by Nobel Laureate Sir Andre Geim used proximity metallic screening. Graphene was positioned lower than a nanometer from a graphite gate, separated by ultrathin hexagonal boron nitride. This excessive Coulomb screening yielded Corridor mobilities past 60 million cm²/Vs—a brand new world document. Quantum Corridor plateaus and oscillations emerged at milli-Tesla discipline strengths, close to Earth’s magnetic discipline.
Each strategies supply distinct benefits—tunability with twisted bilayers versus pristine statement with proximity screening—however collectively, they develop the experimental toolkit for two-dimensional supplies. The advances promise influence in quantum metrology, ultra-sensitive sensing, and energy-efficient electronics, whereas setting the stage for future work on graphene-based moiré quantum techniques.
“These outcomes change what we thought was potential for graphene,” stated Ian Babich, Ph.D. pupil at NUS. “It’s a historic second that opens up unexplored quantum regimes.”
