Abstract
Shot noise refers to the fluctuations in electrical current through a device arising from the discrete nature of the charge-carrying particles. Recent experiments have exploited the fact that the shot noise is proportional to the charge of the carriers to establish fractional quantization of quasiparticles in the fractional quantum Hall effect1,2. By a similar argument, it is expected that when a superconducting reservoir emits Cooper pairs, (which have a charge twice that of an electron) into a short normal-metal wire, the shot noise should be double that obtained for a normal-metal reservoir3,4. Although the charge of Cooper pairs has been well established by flux quantization and tunnel experiments5, doubling of their shot noise has not yet been observed. Here we report a shot-noise experiment using a short diffusive normal-metal superconductor contact, in which we confirm the predicted noise behaviour for double charges. The measurements, taken over a large range of bias current, establish that phase coherence is not required to observe the effect.
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References
Saminadayar,L., Glattli,D. C., Jin,Y. & Etienne,B. Observation of the e/3 fractionally charged Laughlin quasiparticle. Phys. Rev. Lett. 79, 2526–2529 ( 1997).
Reznikov,M., de Picciotto,R., Griffiths, T. G., Heiblum,M. & Umansky,V. Observation of quasiparticles with one-fifth of an electron's charge. Nature 399, 238–240 (1999).
Khlus,V. A. Current and voltage fluctuations in microjunctions between normal metals and superconductors. Sov. Phys. JETP 66, 1243 –1249 (1987).
de Jong,M. J. M. & Beenakker,C. W. J. Doubled shot noise in disordered normal-metal-superconductor junctions. Phys. Rev. B 49, 16070–16073 (1994).
Lafarge,P., Joyez,P., Esteve,D., Urbina,C. & Devoret,M. H. Two-electron quantization of the charge on a superconductor. Nature 365, 422–424 (1993).
Schottky,W. Über spontane Stromschwankungen in verschiedenen Elektrizitätsleitern. Ann. Phys. 57, 541–567 (1918).
Beenakker,C. W. J. & Büttiker,M. Suppression of shot noise in metallic diffusive conductors. Phys. Rev. B 46, 1889–1892 (1992).
Nagaev,K. E. On the shot noise in dirty metal contacts. Phys. Lett. A 169, 103–107 (1992).
Steinbach,A. H., Martinis,J. M. & Devoret, M. H. Observation of hot-electron shot noise in a metallic resistor. Phys. Rev. Lett. 76, 3806– 3809 (1996).
Henny,M., Oberholzer,S., Strunk,C. & Schönenberger,C. 1/3-shot-noise supression in diffusive nanowires. Phys. Rev. B 59, 2871–2880 (1999).
Blanter,Ya. M. & Büttiker,M. Shot noise in mesoscopic conductors. Preprint condmat/9910158 at 〈http://xxx.lanl.gov〉 (1999).
Andreev,A. F. The thermal conductivity of the intermediate state in superconductors. Sov. Phys. JETP 19, 1228–1231 (1964).
Muzykantskii,B. A. & Khmelnitskii,D. E. Quantum shot noise in a normal-metal-superconductor point contact. Phys. Rev. B 50, 3982–3987 ( 1994).
Dieleman,P., Bukkems,H. G., Klapwijk,T. M., Schicke,M. & Gundlach,K. H. Observation of Andreev reflection enhanced shot noise. Phys. Rev. Lett. 79, 3486–3489 (1997).
Hoss,T. et al. Multiple Andreev reflection and giant excess noise in diffusive superconductor/normal-metal/superconductor junctions. Preprint cond-mat 9901129 at 〈http://xxx.lanl.gov〉 (1999).
Jehl,X., Payet-Burin,P., Baraduc,C., Calemczuk,R. & Sanquer,M. Andreev reflection enhanced shot noise in mesoscopic SNS junctions. Phys. Rev. Lett. 83, 1660–1663 (1999).
Nagaev,K. E. Influence of electron-electron scattering on shot noise in diffusive contacts. Phys. Rev. B 52, 4740– 4743 (1995).
Jehl,X., Payet-Burin,P., Baraduc,C., Calemczuk,R. & Sanquer,M. Superconducting quantum interference device based resistance bridge for shot noise measurement on low impedance samples. Rev. Sci. Instrum. 70, 2711– 2714 (1999).
Deutscher,G. & de Gennes,P. G. in Superconductivity (ed. Parks, R. D.) 1005–1034 (Dekker, New York, 1969).
Courtois,H., Charlat,P., Gandit,Ph., Mailly,D. & Pannetier, B. The spectral conductance of a proximity superconductor and the re-entrance effect. J. Low Temp. Phys. 116, 187–214 (1999).
Petrashov,V. T., Shaikhaidarov,R. Sh., Delsing, P. & Claeson,T. Phase-sensitive reentrance into the normal state of mesoscopic SNS structures. JETP Lett. 67, 513–520 (1998).
Artemenko,S. N., Volkov,A. F. & Zaitsev, A. V. On the excess current in microbridges S-c-S and S-c-N. Solid State Commun. 30, 771– 773 (1979).
Pothier,H., Guéron,S., Birge,N. O., Esteve,D. & Devoret,M. H. Energy distribution function of quasiparticles in mesoscopic wires. Phys. Rev. Lett. 79, 3490–3493 (1997).
Altshuler,B. L. & Aronov,A. G. in Electron-Electron Interaction in Disordered Systems (eds Efros, A. L. & Pollak, M.) 1–153 North-Holland, Amsterdam, 1985 ).
Altshuler,B. L., Aronov,A. G., Gershenson, M. E. & Sharvin,Yu. V. Quantum effects in disordered metal films. Sov. Sci. A 9, 223–354 (1987).
Martin,T. Wave packet approach to noise in N-S junctions. Phys. Lett. A 220, 137–142 (1996).
Anantram,M. P. & Datta,S. Current fluctuations in mesoscopic systems with Andreev scattering. Phys. Rev. B 53, 16390–16402 (1996).
Gramespacher,T. & Büttiker,M. Distribution functions and current-correlations in normal-metal-superconductor hetero-structures. Phys. Rev. B 61, 8125 ( 2000).
Torrès,J. & Martin,T. Positive and negative Hanbury-Brown and Twiss correlations in normal metal-superconducting devices. Preprint cond-mat/9906012 at 〈http://xxx.lanl.gov〉 ( 1999).
Lesovik,B. G., Martin,T. & Torrès, J. Josephson frequency singularity in the noise of normal metal-superconductor junctions. Phys. Rev. B 60, 11935–11938 (1999).
Kozhevnikov,A. A., Schoelkopf,R. J., Calvet, L. E., Prober,D. E. & Rooks,M. J. Shot noise measurements in diffusive normal-metal-superconductor (N–S) junctions. J. Low Temp. Phys. 118, 671–678 ( 2000).
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Jehl, X., Sanquer, M., Calemczuk, R. et al. Detection of doubled shot noise in short normal-metal/ superconductor junctions. Nature 405, 50–53 (2000). https://doi.org/10.1038/35011012
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DOI: https://doi.org/10.1038/35011012
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