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Tunnelling between the edges of two lateral quantum Hall systems

Abstract

The edge of a two-dimensional electron system in a magnetic field consists of one-dimensional channels that arise from the confining electric field at the edge of the system1,2,3. The crossed electric and magnetic fields cause electrons to drift parallel to the sample boundary, creating a chiral current that travels along the edge in only one direction. In an ideal two-dimensional electron system in the quantum Hall regime, all the current flows along the edge4,5,6. Quantization of the Hall resistance arises from occupation of N one-dimensional edge channels, each contributing a conductance of e2/h (refs 7,8,9,10,11). Here we report differential conductance measurements, in the integer quantum Hall regime, of tunnelling between the edges of a pair of two-dimensional electron systems that are separated by an atomically precise, high-quality, tunnel barrier. The resultant interaction between the edge states leads to the formation of new energy gaps and an intriguing dispersion relation for electrons travelling along the barrier: for example, we see a persistent conductance peak at zero bias voltage and an absence of tunnelling features due to electron spin. These features are unexpected and are not consistent with a model of weakly interacting edge states. Remnant disorder along the barrier and charge screening may each play a role, although detailed numerical studies will be required to elucidate these effects.

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Figure 1: Structure and differential conductance measurements of our 2D-2D tunnelling device.
Figure 2: Evolution of the differential conductance of 2D-2D tunnelling devices under high magnetic fields.
Figure 3: Schematic energy dependence of the Landau levels in the vicinity of the barrier.

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References

  1. Prange,R. E. & Girvin,S. M. (eds) The Quantum Hall Effect 2nd edn (Springer, New York, 1990).

    Book  Google Scholar 

  2. Das Sarma,S. & Pinczuk,A. (eds) Perspectives in Quantum Hall Effects (Wiley Inter-Science, New York, 1997).

    Google Scholar 

  3. Halperin,B. I. Quantized Hall conductance, current-carrying edge states, and the existence of extended states in a two-dimensional disordered potential. Phys. Rev. B 25, 2185–2188 (1983).

    Article  ADS  Google Scholar 

  4. MacDonald,A. H. & Streda,P. Quantized Hall effect and edge currents. Phys. Rev. B 29, 1616–1619 (1984).

    Article  ADS  Google Scholar 

  5. Apenko,S. M. & Lozovik, Yu. E. J. The quantized Hall effect in strong magnetic fields. J. Phys. C 18, 1197–1203 (1985).

    Article  ADS  Google Scholar 

  6. Fontein,P. F. et al. Spatial potential distribution in GaAs/AlxGa1-xAs heterostructures under quantum Hall conditions studied with the linear electro-optic effect. Phys. Rev.B 43, 12090–3 (1991).

    Article  ADS  CAS  Google Scholar 

  7. Buttiker,M. Absence of backscattering in the quantum Hall effect in multiprobe conductors. Phys. Rev. B 38, 9375–9389 (1988).

    Article  ADS  MathSciNet  CAS  Google Scholar 

  8. Streda,P., Kucera,J. & MacDonald,A. H. Edge states, transmission matrices, and the Hall resistance. Phys. Rev. Lett. 59, 1973–1975 (1987).

    Article  ADS  CAS  Google Scholar 

  9. Jain,J. K. & Kivelson,S. A. Landauer-type formulation of quantum-Hall transport: critical currents and narrow channels. Phys. Rev. B 37, 4276–4279 (1988).

    Article  ADS  CAS  Google Scholar 

  10. Haug,R. J., MacDonald,A. H., Streda,P. & von Klitzing,K. Quantized multichannel magnetotransport through a barrier in two dimensions. Phys. Rev. Lett. 61, 2797–2800 (1988).

    Article  ADS  CAS  Google Scholar 

  11. Washburn,S., Fowler,A. B., Schmid,H. & Kern,D. Quantized Hall effect in the presence of backscattering. Phys. Rev. Lett. 61, 2801–2804 (1988).

    Article  ADS  CAS  Google Scholar 

  12. Yacoby,A. et al. Non-universal conductance quantization in quantum wires. Phys. Rev. Lett. 77, 4612–4615 (1996).

    Article  ADS  CAS  Google Scholar 

  13. Wildoer,J. W. G., Venema,L. C., Rinzler,A. G., Smalley,R. E. & Dekker,C. Electronic structure of atomically resolved carbon nanotubes. Nature 391, 59–62 (1998).

    Article  ADS  CAS  Google Scholar 

  14. Odom,T. W., Huang,J., Kim,P. & Lieber,C. M. Atomic structure and electronic properties of single walled carbon nanotubes. Nature 391, 62–64 (1998).

    Article  ADS  CAS  Google Scholar 

  15. Ishiguro,T., Yamaji,K. & Saito,G. Organic Superconductors 2nd edn (Springer, New York, 1998).

    Book  Google Scholar 

  16. Tessmer,S. H., Glicofridis,P. I., Ashoori,R. C., Levitov,L. S. & Melloch,M. R. Surface charge accumulation imaging of a quantum Hall liquid. Nature 392, 51–54 (1998).

    Article  ADS  CAS  Google Scholar 

  17. McCormick,K. L. et al. Scanned potential microscopy of edge and bulk currents in the quantum Hall regime. Phys. Rev. B 59, 4654–4657 (1999).

    Article  ADS  CAS  Google Scholar 

  18. Goldman,V. J. & Su,B. Resonant tunnelling in the quantum Hall regime: measurement of fractional charge. Science 267, 1010–1012 (1995).

    Article  ADS  CAS  Google Scholar 

  19. Tarucha,S., Honda,T. & Saku,T. Reduction of quantized conductance at low temperatures observed in 2 to 10 µm-long quantum wires. Solid State Commun. 94, 413–18 (1995).

    Article  ADS  CAS  Google Scholar 

  20. Ho,T. L. Oscillatory tunnelling between quantum Hall systems. Phys. Rev. B 50, 4524–4533 (1994).

    Article  ADS  CAS  Google Scholar 

  21. Wulf,U., Gudmundsson,V. & Gerhardts,R. R. Screening properties of the two-dimensional electron gas in the quantum Hall regime. Phys. Rev. B 38, 4218–4230 (1988).

    Article  ADS  CAS  Google Scholar 

  22. Pfeiffer,L. N. et. al. Formation of a high quality two-dimensional electron gas on cleaved GaAs. Appl. Phys. Lett. 56, 1697–1699 (1990).

    Article  ADS  CAS  Google Scholar 

  23. Chang,A. M., Pfeiffer,L. N. & West,K. W. Observation of chiral Luttinger behavior in electron tunnelling into fractional quantum Hall edges. Phys. Rev. Lett. 77, 2538–2341 (1996).

    Article  ADS  CAS  Google Scholar 

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Acknowledgements

We thank S. M. Girvin for insight into the energetics of our 2D-2D device geometry. We also thank R. de Picciotto, A. M. Chang, T. L. Ho and J. P. Eisenstein for discussions.

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Correspondence to W. Kang.

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Kang, W., Stormer, H., Pfeiffer, L. et al. Tunnelling between the edges of two lateral quantum Hall systems. Nature 403, 59–61 (2000). https://doi.org/10.1038/47436

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