Quantum Transport in Two-Dimensional Transistor Systems

Quantum transport in two-dimensional transistor systems encompasses the study of electronic conduction when device dimensions approach the scale of the electron’s wavelength. In atomically thin channels, carriers traverse under ballistic or quasi-ballistic regimes, where scattering is minimised and quantum tunnelling between contacts becomes prominent. Such transport regimes give rise to distinctive phenomena: gate-length scaling beyond the limits of silicon, pronounced short-channel effects, and energy-selective transmission through discrete subbands. Van der Waals heterostructures built from transition metal dichalcogenides, black phosphorus and emerging 2D semiconductors exploit atomically sharp interfaces to tailor channel thickness, electrostatics and contact alignment. Central challenges include minimising contact resistance, controlling quantum confinement, suppressing off-state leakage and engineering subthreshold swing near its thermionic limit. Progress in vertical and lateral device architectures, combined with advanced computational modelling of electron-phonon interactions, has enabled sub-nanometre gate lengths and high on-off ratios. These advances underpin the next generation of ultra-scaled logic, low-power electronics and specialised applications such as radiation-hardened circuits and integrated sensors.

Research from Nature Portfolio

Recent studies have demonstrated self-aligned fabrication methods for vertical channel transistors, achieving gate lengths below one nanometre and channel lengths under fifty nanometres in MoS₂ heterostructures. By mechanically folding graphene–boron nitride–MoS₂ stacks, source and drain electrodes precisely flank the channel, yielding on-off ratios exceeding 10⁵ and substantially enhanced on-state currents at modest bias. This architecture underlines the potential of van der Waals integration for ultimate scaling. Complementing experimental advances, foundational assessments of material-device-circuit co-optimisation have established design guidelines for sub-5 nm gate-length FETs. These analyses emphasise the requirement for low effective mass materials, anisotropic carrier transport, and aggressive scaling of supply voltage and oxide thickness to satisfy energy-delay metrics. The work provides a roadmap linking intrinsic material properties to system-level performance for future high-performance logic nodes.

Quantum Transport in Two-Dimensional Transistor Systems publication trend

The graph below shows the total number of articles in quantum transport in two-dimensional transistor systems across all publications each year (not limited to Nature Index journals).

Technical terms

Quantum transport: Carrier motion governed by wave-like behaviour, including tunnelling and discrete energy levels.

Ballistic transport: Electron propagation through a channel with negligible scattering over its length.

Subthreshold swing: Voltage required to increase the current by one decade in the FET’s subthreshold region, indicating switching steepness.

Van der Waals heterostructure: Stack of atomically thin materials held together by weak interlayer forces, forming clean interfaces.

Contact resistance: Electrical resistance at the junction between a metal electrode and a semiconductor channel.

References

1. Ultrashort vertical-channel MoS2 transistor using a self-aligned contact. Nature Communications (2024).
2. Material-Device-Circuit Co-optimization of 2D Material based FETs for Ultra-Scaled Technology Nodes. Scientific Reports (2017).
3. High-throughput design of functional-engineered MXene transistors with low-resistive contacts. npj Computational Materials (2022).
4. Computational study of transition metal dichalcogenide cold source MOSFETs with sub-60 mV per decade and negative differential resistance effect. npj 2D Materials and Applications (2022).
5. Performance Assessment of Ultrascaled Vacuum Gate Dielectric MoS2 Field-Effect Transistors: Avoiding Oxide Instabilities in Radiation Environments. Micromachines (2024).