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Abstract

The transport properties of the semimetallic quasi-one- dimensional S = 1/2 antiferromagnet Yb4As3 have been studied by performing low-temperature (T greater than or equal to 0.02 K) and high magnetic-field (B less than or equal to 60 T) measurements of the electrical resistivity rho(T, B). For T greater than or similar to 2 K a 'heavy-fermion'-like behavior Deltarho(T) = AT(2) with huge and nearly field-independent coefficient A approximate to 3 muOmega cm/K-2 is observed, whereas at lower temperatures rho(T) deviates from this behavior and slightly increases to the lowest T. In B > 0 and T less than or similar to 6 K the resistivity shows an anomalous magnetic-hi story dependence together with an unusual relaxation behavior. In the isothermal resistivity Shubnikov-de Haas (SdH) oscillations, arising from a low-density system of mobile As-4p holes, with a frequency of 25 T have been recorded. From the T- and B-dependence of the SdH oscillations an effective carrier mass of (0.275 +/- 0.005)m(0) and a charge-carrier mean-free path of 215 Angstrom are determined. Furthermore, in B greater than or equal to 15 T, the system is near the quantum limit and spin-splitting effects are observed.