Universality in antiferromagnetic strange metals | |
Article | |
关键词: QUANTUM CRITICAL-POINT; SPIN-FERMION MODEL; RENORMALIZATION-GROUP; SYSTEMS; | |
DOI : 10.1103/PhysRevB.93.165114 | |
来源: SCIE |
【 摘 要 】
We propose a theory of metals at the spin-density-wave quantum-critical point in spatial dimension d = 2. We provide a first estimate of the full set of critical exponents (dynamical exponent z = 2.13, correlation length upsilon= 1.02, spin susceptibility gamma= 0.96, electronic non-Fermi liquid eta(f)(tau) = 0.53, spin-wave Landau damping eta(b)(tau)= 1.06), which determine the universal power laws in thermodynamics and response functions in the quantumcritical regime relevant for experiments in heavy-fermion systems and iron pnictides. We present approximate numerical and analytical solutions of Polchinski-Wetterich-type flow equations with soft frequency regulators for an effective action of electrons coupled to spin-wave bosons. Performing the renormalization group in frequency instead of momentum space allows to track changes of the Fermi-surface shape and to capture Landau damping during the flow. The technique is easily generalizable from models retaining only patches of the Fermi surface to full, compact Fermi surfaces.
【 授权许可】
Free