Ra. Webb et al., INTRINSIC DECOHERENCE AND LOSS OF FERMI-LIQUID BEHAVIOR IN MESOSCOPICSYSTEMS, Fortschritte der Physik (Berlin. Wiley-VCH), 46(6-8), 1998, pp. 779-789
We present measurements of the phase coherence time tau(phi), and elec
tron-electron energy relaxation time tau(ee) in mesoscopic Au wires an
d clearly show that both become temperature independent at low tempera
tures. We show that magnetic impurities are not responsible for the ob
served saturations and that the spin-flip scattering time shows an unu
sual growth with decreasing temperature. All these observations are si
gnatures of the breakdown of the Fermi liquid theory of electron-elect
ron interaction in diffusive systems. We propose that zero-point fluct
uations of the environment of the phase coherent electrons are respons
ible for the observed saturation of tau(phi) and introduce a new funct
ional form for the temperature dependence and present the results of a
calculation for the saturation value of tau(phi). This explains the o
bserved temperature dependence of most 1D and 2D systems reported to d
ate.