Abstract

With help of built-in spontaneous and piezoelectric polarization, a high mobility two-dimensional electron gas was achieved at a ZnO/MgZnO heterointerface [1], where both QHE and FQHE were observed due to strong electron-electron correlation [2][3].

Recently we succeed to fabricate the first split-gate defined quasi-1D channel in this ZnO system and measure in a dilution fridge. In presence of low magnetic fields, we investigated the reflected edge state and observed the dominating odd-filling factor states. However in absence of magnetic fields, the system disorder result in irregular 1D conductance plateaux. By applying asymmetry bias we distinguished the 1D conductance plateaux with ΔG= e2/h (ΔG= 2e2/h in GaAs systems), indicating electrons in ZnO are spin-polarised even at zero magnetic fields. In virtue of edge states, we avoid the impurity state and perform DC bias spectroscopy measurement to estimate the 1D subband energy in this oxide system. In future we wish to implement the single electron spin transport with surface acoustic waves on this ZnO heterostructure.