Possibility of chiral-surface-state originated bulk quantum Hall effect ineta-Mo4O11 crystal

Magnetotransport properties have been measured for quasi-two-dimensional ox ide eta-Mo4O11 at low temperatures 0.3-4.2 K in magnetic fields up to 10 T using both bulk contacts and edge contacts methods. In the former case, nor mal Shubnikov-de Haas oscillations are observed In the latter case, the Hal l resistivity pH and transverse magnetoresistance along the c-axis exhibits clear plateaus and minima, respectively, while the longitudinal magnetores istance along the a*-axis shows a profound peak around 9 T. At the plateaus rho(H) is quantized as, rho(H)(nu)/rho(H)(nu=2) = 2/nu(nu: filling factor) , which suggests that a 2D chiral-surface-state appears near the bulky crys tal edge.