Continuous-Time Quantum Monte Carlo Study of Local Non-Fermi Liquid State in the Multichannel Anderson Model

The impurity Green's function Gf in the local non-Fermi liquid state is evaluated by means of the continuous-time quantum Monte Carlo method extended to the multichannel Anderson model. For N=M (where N and M are numbers of spin components and channels, respectively), Gf is expressed as -Im Gf(w+i0) = c - b |w|^{1/2}, and the zero-frequency value c depends only on N (=M). A corresponding impurity self-energy at low frequencies is composed of two parts: a resonance term related to c, and a non-Fermi liquid term proportional to |w|^{1/2}. The characteristic energy scale is discussed in terms of the non-Fermi liquid term in the self-energy.