We report the fabrication and the characterization of a transistor based on modulation-dope (delta-dope) InAs/InP core shell nanowire which was grown on InAs (111) substrate by VLS techniques using MBE. The mobility of the core shell nanowire was 13,600 cm(2)/Vs at room temperature, which is approximately 7-fold increase comparing to the simple InAs nanowire. Estimated mobility at V-ds=0.1 V increased from 13,600 cm(2)/Vs at RT to 15,600 cm(2)/Vs at low temperature. A gate voltage dependent crossover from weak-localization to weak-antilocalization was observed. We extracted the spin relaxation length and coherence length using a quasi-one-dimensional model of the conductance. The effectiveness of the InP shell passivation was confirmed. (c) 2013 Elsevier B.V. All rights reserved.