Abstract
The fractional quantum Hall effect1 occurs in the conduction properties of a two-dimensional electron gas subjected to a strong perpendicular magnetic field. In this regime, the Hall conductance shows plateaux, or fractional states, at rational fractional multiples of e 2/h, where e is the charge of an electron and h is Planck's constant. The explanation1,2,3 of this behaviour invokes strong Coulomb interactions among the electrons that give rise to fractionally charged quasiparticles which can be regarded as non-interacting current carriers1,2,3,4,5. Previous studies4,5 have demonstrated the existence of quasiparticles with one-third of an electron's charge, the same fraction as that of the respective fractional state. An outstanding ambiguity is therefore whether these studies measured the charge or the conductance. Here we report the observation of quasiparticles with a charge of e /5 in the 2/5 fractional state, from measurements of shot noise in a two-dimensional electron gas4. Our results imply that charge can be measured independently of conductance in the fractional quantum Hall regime, generalizing previous observations of fractionally charged quasiparticles.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 51 print issues and online access
$199.00 per year
only $3.90 per issue
Buy this article
- Purchase on Springer Link
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
References
Laughlin, R. B. Anomalous quantum Hall effect: an incompressible quantum fluid with fractional charge excitations. Phys. Rev. Lett. 50, 1395–1398 (1983).
Laughlin, R. B. Primitive and composite ground states in the fractional quantum Hall effect. Surf. Sci. 142, 163–172 (1984).
Prange, R. E. & Girvin, S. M. (eds) The Quantum Hall Effect (Springer, New York, (1987).
de Picciotto, R. et al. Direct observation of a fractional charge. Nature 389, 162–164 (1997).
Saminadayar, L., Glattli, D. C., Jin, Y. & Etienne, B. Observation of the e/3 fractionally charged Laughlin quasiparticles. Phys. Rev. Lett. 79, 2526–2529 (1997).
Kane, C. L. & Fisher, M. P. A. Nonequilibrium noise and fractional charge in the quantum Hall effect. Phys. Rev. Lett. 72, 724–727 (1994).
Fendley, A., Ludwig, W. W. & Saleur, H. Exact nonequilibrium dc shot noise in Luttinger liquids and fractional quantum Hall devices. Phys. Rev. Lett. 75, 2196–2199 (1995).
de Chamon, C., Freed, D. E. & Wen, X. G. Tunneling and quantum shot noise in Luttinger liquids. Phys. Rev. B 51, 2363–2378 (1995).
Jain, J. K. Composite-fermion approach to the fractional quantum Hall effect. Phys. Rev. Lett. 63, 199–202 (1989).
Halperin, B. in New Perspectives in Quantum Hall Effect (eds Das Sarma, S. & Pinzuk, A.) 225–263 (Wiley, New York, (1997).
Lesovik, G. B. Excess quantum shot noise in 2D ballistic point contacts. JETP Lett. 49, 592–594 (1989).
Reznikov, M., Heiblum, M., Shrtikman, H. & Mahalu, D. Temporal correlations of electrons: suppression of shot noise in a ballistic point contact. Phys. Rev. Lett. 75, 3340–3334 (1995).
Kumar, A., Saminadayar, L., Glattli, D. C., Jin, Y. & Etienne, B. Experimental test of the quantum shot noise reduction theory. Phys. Rev. Lett. 76, 2778–2781 (1996).
Reznikov, M. et al. Quantum shot noise. Superlattices Microstruct. 23, 901–915 (1998).
de Picciotto, R. Shot noise of non-interacting composite fermions.Preprint cond-mat/982221 at 〈xxx.lanl.gov〉 (1998).
Sandler, N. P., de Chamon, C. & Fradkin, E. Noise measurements and fractional charge in fractional quantum Hall liquids. Phys. Rev. B (in the press); preprint cond-mat/9806335 at 〈xxx.lanl.gov〉 (1998).
de Picciotto, R. et al. Direct observation of a fractional charge. Phys. B 249–251;, 395–400 (1998).
Isakov, S., Martin, T. & Ouvry, S. Conductance and shot noise for particles with exclusion statistics.Preprint cond-mat/9811391 at 〈xxx.lanl.gov〉 (1998).
Fendley, P. & Saleur, H. Nonequilibrium dc noise in a Luttinger liquid with an impurity. Phys. Rev. B 54, 10845–10854 (1996).
Martin, T & Landauer, R. Wave packet approach to noise in multichannel mesoscopic systems. Phys. Rev. B 45, 1742–1755 (1992).
Acknowledgements
We thank G. Bunin for manufacturing the transistors for the cooled preamplifier, and D. Mahalu for performing the e-beam lithography. This work was partly supported by the Israeli Science Foundation, the German-Israeli Foundation and the Israeli Ministry of Science.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Reznikov, M., Picciotto, R., Griffiths, T. et al. Observation of quasiparticles with one-fifth of an electron's charge. Nature 399, 238–241 (1999). https://doi.org/10.1038/20384
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1038/20384
This article is cited by
-
Shot noise does not always provide the quasiparticle charge
Nature Physics (2022)
-
Microwave photons emitted by fractionally charged quasiparticles
Nature Communications (2019)
-
Collective fluorescence enhancement in nanoparticle clusters
Nature Communications (2011)
-
Observation of a quarter of an electron charge at the ν = 5/2 quantum Hall state
Nature (2008)
-
Microscopic manifestation of the spin phase transition at filling factor 2/3
Nature Physics (2007)
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.
