A new classification scheme for relevant couplings in renormalization group transformations

作者：Shih Hong Yan^*; Huang Wen Min; Hsu Sze Bi; Lin Hsiu Hau

来源：Physica C-Superconductivity and Its Applications, 2010, 470: S964-S965.

DOI：10.1016/j.physc.2009.12.019

• Renormalization group
• Crossover scaling
• Spin gap
• Relevant coupling

The phase diagram for interacting electrons can be determined from the one-loop renormalization group (RG) analysis in weak coupling. However, the lack of analytic solutions for the RG flow equations often makes identifying the relevant and irrelevant couplings vague. Here we propose a scaling Ansatz to classify the relevant couplings without ambiguity. This powerful classification scheme allows us to clarify a controversial quantum phase transition in the doped two-leg ladder. With the help of the scaling Ansatz, the mistaken quantum phase transition turns out to be a non-trivial crossover with an interesting hierarchy of excitation gaps. The classification scheme we developed is rather general and can be applied to other renormalization group methods as well.

• 出版日期2010-12
• 单位清华大学