Evidence for Charging Effects in CdTe/CdMgTe Quantum Point Contacts
  Here we report on fabrication and low temperature magnetotransport measurements of quantum point contacts patterned from a novel two-dimensional electron system - CdTe/CdMgTe modulation doped heterostructure. From the temperature and bias dependence we ascribe the reported data to evidence for a weakly bound state which is naturally formed inside a CdTe quantum constrictions due to charging effects. We argue that the spontaneous introduction of an open dot is responsible for the replacement of flat conductance plateaus by quasi-periodic resonances with amplitude less than 2e^{2}/h, as found in our system. Additionally, below 1 K a pattern of weaker conductance peaks, superimposed upon wider resonances, is also observed. 
M. Czapkiewicz, V. Kolkovsky, P. Nowicki, M. Wiater, T. Wojciechowski,   T. Wojtowicz and J. Wr\'obel
cond-mat.mes-hall