Quantum Monte Carlo Study on Impurity Pinning in One-Dimensional Interacting Electron Systems–Competition between Charge Density and Superconducting Fluctuations–

Abstract

Effects of random impurities on one-dimensional interacting electron systems are studied by use of the quantum Monte Carlo method and the phase variable representation of charge density and superconducting fluctuations. The impurities pin the phase variable of charge density fluctuation, whereas the quantum fluctuation around the pinned state reduces the pinning effect yielding increase of the superconducting fluctuation since the charge density and the superconducting fluctuations are complementary to each other. Such interplay between randomness and interactions is shown explicitly by calculating spatial dependence of quantum fluctuations, metastable states and correlation functions for superconductivity. Quantum character of metastable states is discussed. It is found that superconducting state is more sensitive to impurities than charge density wave state when the interaction between electrons is weak.