Solvable Theory of a Strange Metal at the Breakdown of a Heavy Fermi Liquid

Abstract

We introduce an effective theory for quantum critical points (QCPs) in heavy fermion systems, involving a change in carrier density without symmetry breaking. Our new theory captures a strongly coupled metallic QCP, leading to robust marginal Fermi liquid transport phenomenology, and associated linear in temperature ($T$) "strange metal" resistivity, all within a controlled large $N$ limit. In the parameter regime of strong damping of emergent bosonic excitations, the QCP also displays a near-universal "Planckian" transport lifetime, ${\tau }_{\mathrm{tr}}\sim \hslash /(k_{B}T)$. This is contrasted with the conventional so-called "slave boson" theory of the Kondo breakdown, where the large $N$ limit describes a weak coupling fixed point and non-trivial transport behavior may only be obtained through uncontrolled $1/N$ corrections. We also compute the weak-field Hall coefficient within the effective model as the system is tuned across the transition. We further find that between the two plateaus, reflecting the different carrier densities in the two Fermi liquid phases, the Hall coefficient can develop a peak in the critical crossover regime, like in recent experimental findings, in the parameter regime of weak boson damping.

25 pages, 10 figures

References in corpus (13)

• Heavy Fermions and Quantum Phase Transitions
• Weak magnetism and non-Fermi liquids near heavy-fermion critical points
• Fractionalized Fermi liquids
• Low energy effective theory of Fermi surface coupled with U(1) gauge field in 2+1 dimensions
• Fermi-surface collapse and dynamical scaling near a quantum critical point
• DC resistivity at the onset of spin density wave order in two-dimensional metals
• Sum Rules and Ward Identities in the Kondo Lattice
• From the pseudogap metal to the Fermi liquid using ancilla qubits
• Multi-scale fluctuations near a Kondo Breakdown Quantum Critical Point
• Dirac Fast Scramblers
• Are Heavy Fermion Strange Metals Planckian?
• Thermopower across the phase diagram of the cuprate La${}_{1.6-x}$Nd${}_{0.4}$Sr${}_x$CuO${}_4$ : signatures of the pseudogap and charge-density-wave phases
• Skewed Non-Fermi Liquids and the Seebeck Effect

Cited by in corpus (4)

• Large $N$ theory of critical Fermi surfaces
• Gate-tunable heavy fermion quantum criticality in a moiré Kondo lattice
• Small to large Fermi surface transition in a single band model, using randomly coupled ancillas
• Can electronic quantum criticality drive phonon-induced linear-in-temperature resistivity?