Hall coefficients and resistivities of Bi_(2+x)Sr_(2-x)CuO_(y) single crystals: The presence of a mobility edge in correlated two-dimensional electron system

摘要

Hall coefficients and resistivities of a series of Bi_(2+x)Sr_(2-x)CuO_(y) single crystals were measured to investigate the relation between the carrier concentration n and the resistivity-minimum temperature T_(min). The T_(min) was found to obey a simple linear relation: T_(min)∝n_(c)-n, where n_(c)approx-4.2×10~(21) cm~(-3) is a critical carrier concentration. A model of two-dimensional electron systems with a mobility edge was introduced to explain this linear relation, and the presence of a mobility edge in two-dimensional copper-oxide-based metals was suggested.