We study the critical behavior driven by potential quantum critical points (QCPs) termed as
τ0,x,y,z-Type QCPs in the
d-wave cuprate superconductors. Within the framework of the renormalization group approach, we construct the coupled flow equations of all interaction parameters and obtain several unique properties. On one hand, the interaction parameters flow toward several fixed points (FPs) at certain critical energy scales. We identify two different types of FPs designated at the clean limit. FP-I is characterized by the divergence of the quadratic parameter and exhibits robustness against variations in interaction parameters. In contrast, FP-II is dominated by the cubic and quartic interaction parameters, and it is sensitive to initial conditions, leading to five subclasses. Besides, we find that disorder scattering can influence fermion velocities and critical energy scales, and even destabilize certain FPs around the
τx,z-QCPs, driving the system toward a preempted disorder-induced FP. On the other hand, we find that quantum fluctuations play a critical role in shaping the critical temperature (
Tc) as the system approaches these QCPs. Near the
τx-QCP,
Tc is considerably suppressed for both FP-I and FP-II. In contrast, near the
τ0-QCP,
Tc undergoes a substantial decrease for FP-I but only a slight decrease for FP-II. Conversely,
Tc exhibits an increasing trend near the
τy-QCP, with a pronounced peak at
vΔ0/vF0∼0.25. However, numerical analysis suggests that the
τz-QCP is unlikely to be physically realizable. Additionally, we realize that
Tc can also be modified by the emergence of disorder-induced FPs in the vicinity of the
τx-QCP. These findings would provide valuable insights into the critical low-energy properties of
d-wave cuprate superconductors and related materials.
The
d-wave high-temperature cuprate superconductor may exhibit a nematic ordering transition at zero temperature. Near the quantum critical point, the coupling between gapless nodal quasiparticles and nematic order parameter fluctuation can result in unusual behaviors, such as extreme anisotropy of fermion velocities. We study the disorder effects on the nematic quantum critical behavior and especially on the flow of fermion velocities. The disorders that couple to nodal quasiparticles are divided into three types: random mass, random gauge field, and random chemical potential. A renormalization-group analysis shows that random mass and random gauge field are both irrelevant and, thus, do not change the fixed point of extreme velocity anisotropy. However, the marginal interaction due to random chemical potential destroys this fixed point and makes the nematic phase transition unstable.