摘要
An impurity in a Tomonaga-Luttinger liquid leads to a crossover between the short- and long-distance regime which describes many physical phenomena. However, a calculation of the entire crossover of correlation functions over different length scales has been difficult. We develop a powerful numerical method based on the infinite density matrix renormalization group. By utilizing infinite boundary conditions we can obtain correlation functions within a finite-size window that contains the impurity. For the S=1/2 chain, we demonstrate that a full crossover can be precisely obtained, and that their limiting behaviors show a good agreement with field-theory predictions.