Resonant Tunneling Phenomena in Two-Dimensional Materials

Resonant tunnelling in atomically thin materials arises when charge carriers traverse potential barriers via discrete energy states, yielding pronounced peaks in conductance and, under certain conditions, negative differential resistance. The advent of van der Waals heterostructures—stacks of graphene, hexagonal boron nitride and transition-metal dichalcogenides—has provided an unprecedented platform for exploring these effects at ambient and cryogenic temperatures. Interfaces engineered with precise layer thickness and twist angle control permit phonon- and exciton-assisted tunnelling, while localised defect states within insulating barriers can serve as spectroscopic probes of many-body interactions. Beyond fundamental interest in quantum confinement and electron-electron correlations, resonant tunnelling devices in two-dimensional materials promise ultra-fast oscillators, sensitive photodetectors and novel optoelectronic emitters. Advances in time-resolved tunnelling spectroscopy further enable direct observation of carrier dynamics, revealing lifetimes, relaxation pathways and emergent collective excitations. Together, these developments chart a path towards tunable quantum devices that harness the unique electronic, optical and spin properties of two-dimensional crystals.

Research from Nature Portfolio

Recent studies have demonstrated that excitons in transition-metal dichalcogenide monolayers can mediate resonant tunnelling between graphene and metal electrodes separated by hexagonal boron nitride, producing sharp conductance features at bias voltages matching exciton energies. This exciton-assisted process operates without direct charge injection into the semiconductor layer, opening routes to hybrid optoelectronic functionality in van der Waals stacks. In parallel, investigations of electron–electron interactions in graphene/hBN junctions have uncovered a magnetically induced Coulomb gap at low temperatures when tunnelling through single defect states, highlighting the role of many-body physics in shaping the resonant spectrum. Complementing these recent findings, foundational work on synthetic heterostructures combining graphene with molybdenum and tungsten dichalcogenides has established room-temperature negative differential resistance in atomically thin multi-junction diodes, underscoring the viability of two-dimensional resonant tunnelling devices for high-frequency applications.

Resonant Tunneling Phenomena in Two-Dimensional Materials publication trend

The graph below shows the total number of articles in resonant tunneling phenomena in two-dimensional materials across all publications each year (not limited to Nature Index journals).

Technical terms

Resonant tunnelling: Quantum mechanical transmission through a barrier at discrete energy levels, producing peaks in conductance and possible negative differential resistance.

Van der Waals heterostructure: A stack of two-dimensional crystals assembled layer by layer, held together by van der Waals forces, offering atomically sharp interfaces.

Exciton: A bound electron–hole pair within a semiconductor, capable of influencing electrical transport when its energy aligns with tunnelling states.

Negative differential resistance: A regime where current decreases with increasing voltage beyond a resonance, enabling electronic oscillators and memory elements.

References

1. Exciton-assisted electron tunnelling in van der Waals heterostructures. Nature Materials (2023).
2. Time, momentum, and energy resolved pump-probe tunneling spectroscopy of two-dimensional electron systems. Nature Communications (2023).
3. A magnetically-induced Coulomb gap in graphene due to electron-electron interactions. Communications Physics (2023).
4. Phonon-Assisted Resonant Tunneling of Electrons in Graphene–Boron Nitride Transistors. Physical Review Letters (2016).
5. Atomically thin resonant tunnel diodes built from synthetic van der Waals heterostructures. Nature Communications (2015).
6. Twist-controlled resonant tunnelling between monolayer and bilayer graphene. Applied Physics Letters (2015).
7. Resonant Light Emission from Graphene/Hexagonal Boron Nitride/Graphene Tunnel Junctions. Nano Letters (2021).