Einzelelektronentransistoren im Regime kleiner Widerstaende

In this thesis we report on the experimental investigation of Aluminum-Alumina-Aluminum single-electron transistors with tunnel junction resistances of the order of R_K and on the implementation of the measurement setup necessary for this. In the regime of low resistive tunnel junctions tunnel processes beyond the orthodox theory contribute clearly to the transport. The only two sample parameters which enter the theoretical descriptions are the charging energy E_c and the coupling strength #alpha# = R_K/R _p_a_r_a_l_l_e_l, where R _p_a_r_a_l_l_e_l denotes the parallel resistance of the junctions. The transistors investigated are fabricated with a special layout which allows the direct measurement of #alpha#. On such transistors with coupling strengths alpha from 0.8 to 6 the minimum and maximum linear-response conductance, G_m_i_n and G_m_a_x resp., were extracted from the coulomb oscillations as a function of temperature in the range from 28 mK to 18 K. The results are compared with the predictions of a second order perturbation theory, a semiclassical analytical description and quantum Monte-Carlo calculations (QMC). For G_m_a_x(T), a good agreement with the perturbation theory is found for samples with #alpha# < 2. For higher #alpha# an increasing deviation is observed. For G_m_i_n(T) deviations are observed for all values of alpha which grow with increasing alpha. The semiclassical approach describes G_m_i_n(T) and G_m_a_x(T) at high temperatures well. For the QMC calculations good agreement is observed in the entire temperature range. (orig.)SIGLEAvailable from TIB Hannover: ZA 5141(6712) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman