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5
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84927416744
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``Persistent Currents in Mesoscopic Rings: Theory and Experiments'' (to be published).
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Riedel, E.K.1
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6
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84927416743
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Y. Imry, in ``Quantum Coherence in Mesoscopic Systems,'' edited by B. Kramer, Proceedings of the NATO Advanced Study Institute, 1990 (Plenum, New York, to be published).
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16
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84927416742
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We put kB= hbar = 1 except in the final results.
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17
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84927416741
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The following relation has been derived first by Imry (Ref. 6), Eq. (4.11).
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20
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84927416740
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Note that in the present paper, the density of states is per one spin direction. Furthermore, note that the Cooperon and diffusion contributions are the same for systems with time-reversal symmetry.
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21
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84927416739
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Various mechanisms are known to contribute to the rate gamma for destruction of phase coherence: (a) inelastic scattering, which is negligible here since it is certainly smaller than 2 π T; (b) magnetic-field penetration, which contributes the rate case 1 over 3 D ( e B a / hbar c )2, where a is the width of the ring; (c) spin-flip scattering; and (d) spin-orbit scattering in the mesoscopic sample. There may be an additional mechanism which has not been discussed in the past: (e) a contribution of the order of Δ = 1 / scrN0scrV, which is the average level spacing. This is, however, a conjecture which deserves further investigation.
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22
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3943084504
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second following Letter, have independently obtained the same relation. I have learned from this preprint that one should retain the rate gamma though, presently, its physics is not so clear;
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(1991)
Phys. Rev. Lett.
, vol.66
, pp. 88
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Altshuler, B.L.1
Gefen, Y.2
Imry, Y.3
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23
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84927416738
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see Ref. 14.
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24
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84927416736
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The average with respect to impurity configurations corresponds in the experiment of Ref. 6 to an average over 107 different realization of mesoscopic copper rings.
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25
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84927416734
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H. Bouchiat has just now informed me that a recent analysis of the computer simulations of Refs. 3 and 4 reveals a reasonable agreement with Eq. (14).
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26
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84927416725
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I remark that the final result is unchanged if μx is taken to be spin independent.
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28
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84927416724
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The subscript xx + means that the second time should be considered as later than the first one.
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30
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84927416723
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A simple consequence of this fact: There is no difference whether the 107 copper rings are connected electrically or not. On the other hand, the case of global charge neutrality may possibly be realized in semiconductors where the screening length is comparable to the dimensions of the ring [H. Bouchiat (private communication)].
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31
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84927416722
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``Nonlinear Diamagnetic Response in Mesoscopic Rings of Superconductors above Tc'' (to be published).
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Ambegaokar, V.1
Eckern, U.2
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32
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84927416721
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I wish to thank Dr. U. Eckern for pointing out the relevance of these fluctuations and of a finite value of gamma.
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34
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84927416720
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Note, however, that the conductivity depends only on the electrons at the Fermi level whereas presently, all electrons contribute to the density.
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35
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84927416719
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The relevant coefficient is the inverse density of states 1 / scrN0.
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