標題: Quantum criticality of the two-channel pseudogap Anderson model: universal scaling in linear and non-linear conductance
作者: Wu, Tsan-Pei
Wang, Xiao-Qun
Guo, Guang-Yu
Anders, Frithjof
Chung, Chung-Hou
電子物理學系
Department of Electrophysics
關鍵字: quantum criticality;two-channel Kondo physics;quantum phase transitions;non-equilibrium quantum transport
公開日期: 5-May-2016
摘要: The quantum criticality of the two-lead two-channel pseudogap Anderson impurity model is studied. Based on the non-crossing approximation (NCA) and numerical renormalization group (NRG) approaches, we calculate both the linear and nonlinear conductance of the model at finite temperatures with a voltage bias and a power-law vanishing conduction electron density of states, rho(c)(omega) alpha | omega-mu(F)|(r) (0 < r < 1) near the Fermi energy mu(F). At a fixed leadimpurity hybridization, a quantum phase transition from the two-channel Kondo (2CK) to the local moment (LM) phase is observed with increasing r from r = 0 to r = r(c) < 1. Surprisingly, in the 2CK phase, different power-law scalings from the well-known root T or root V form is found. Moreover, novel power-law scalings in conductances at the 2CK-LM quantum critical point are identified. Clear distinctions are found on the critical exponents between linear and non-linear conductance at criticality. The implications of these two distinct quantum critical properties for the non-equilibrium quantum criticality in general are discussed.
URI: http://dx.doi.org/10.1088/0953-8984/28/17/175003
http://hdl.handle.net/11536/133623
ISSN: 0953-8984
DOI: 10.1088/0953-8984/28/17/175003
期刊: JOURNAL OF PHYSICS-CONDENSED MATTER
Volume: 28
Issue: 17
Appears in Collections:Articles