TY  JOUR
T1  Quantum criticality of the twochannel pseudogap Anderson model
T2  Universal scaling in linear and nonlinear conductance
AU  Wu, Tsan Pei
AU  Wang, Xiao Qun
AU  Guo, Guang Yu
AU  Anders, Frithjof
AU  Chung, ChungHou
PY  2016/4/5
Y1  2016/4/5
N2 
The quantum criticality of the twolead twochannel pseudogap Anderson impurity model is studied. Based on the noncrossing 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 powerlaw vanishing conduction electron density of states, ρ
c
(ω) ∝ ω  μ
F

r
(0 < r < 1) near the Fermi energy μ
F
. At a fixed leadimpurity hybridization, a quantum phase transition from the twochannel 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 powerlaw scalings from the wellknown √T or √V form is found. Moreover, novel powerlaw scalings in conductances at the 2CKLM quantum critical point are identified. Clear distinctions are found on the critical exponents between linear and nonlinear conductance at criticality. The implications of these two distinct quantum critical properties for the nonequilibrium quantum criticality in general are discussed.
AB 
The quantum criticality of the twolead twochannel pseudogap Anderson impurity model is studied. Based on the noncrossing 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 powerlaw vanishing conduction electron density of states, ρ
c
(ω) ∝ ω  μ
F

r
(0 < r < 1) near the Fermi energy μ
F
. At a fixed leadimpurity hybridization, a quantum phase transition from the twochannel 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 powerlaw scalings from the wellknown √T or √V form is found. Moreover, novel powerlaw scalings in conductances at the 2CKLM quantum critical point are identified. Clear distinctions are found on the critical exponents between linear and nonlinear conductance at criticality. The implications of these two distinct quantum critical properties for the nonequilibrium quantum criticality in general are discussed.
KW  nonequilibrium quantum transport
KW  quantum criticality
KW  quantum phase transitions
KW  twochannel Kondo physics
UR  http://www.scopus.com/inward/record.url?scp=84963537640&partnerID=8YFLogxK
U2  10.1088/09538984/28/17/175003
DO  10.1088/09538984/28/17/175003
M3  Article
AN  SCOPUS:84963537640
VL  28
JO  Journal of Physics Condensed Matter
JF  Journal of Physics Condensed Matter
SN  09538984
IS  17
M1  175003
ER 