TY - JOUR
T1 - Quantum criticality of the two-channel pseudogap Anderson model
T2 - Universal scaling in linear and non-linear conductance
AU - Wu, Tsan Pei
AU - Wang, Xiao Qun
AU - Guo, Guang Yu
AU - Anders, Frithjof
AU - Chung, Chung-Hou
PY - 2016/4/5
Y1 - 2016/4/5
N2 -
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, ρ
c
(ω) ∝ |ω - μ
F
|
r
(0 < r < 1) near the Fermi energy μ
F
. At a fixed lead-impurity 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 √T or √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.
AB -
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, ρ
c
(ω) ∝ |ω - μ
F
|
r
(0 < r < 1) near the Fermi energy μ
F
. At a fixed lead-impurity 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 √T or √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.
KW - non-equilibrium quantum transport
KW - quantum criticality
KW - quantum phase transitions
KW - two-channel Kondo physics
UR - http://www.scopus.com/inward/record.url?scp=84963537640&partnerID=8YFLogxK
U2 - 10.1088/0953-8984/28/17/175003
DO - 10.1088/0953-8984/28/17/175003
M3 - Article
AN - SCOPUS:84963537640
VL - 28
JO - Journal of Physics Condensed Matter
JF - Journal of Physics Condensed Matter
SN - 0953-8984
IS - 17
M1 - 175003
ER -