Quantum phase transition at non-zero doping in a random $t$-$J$ model

Abstract

We present exact diagonalization results on finite clusters of a $t$-$J$ model of spin-1/2 electrons with random all-to-all hopping and exchange interactions. We argue that such random models capture qualitatively the strong local correlations needed to describe the cuprates and related compounds, while avoiding lattice space group symmetry breaking orders. The previously known spin glass ordered phase in the insulator at doping $p=0$ extends to a metallic spin glass phase up to a transition $p=p_c\approx 1/3$. The dynamic spin susceptibility shows signatures of the spectrum of the Sachdev-Ye-Kitaev models near $p_c$. We also find signs of the phase transition in the entropy, entanglement entropy and compressibility, all of which exhibit a maximum near $p_c$. The electron energy distribution function in the metallic phase is consistent with a disordered extension of the Luttinger-volume Fermi surface for $p>p_c$, while this breaks down for $p<p_c$.

5 pages, 4 figures

References in corpus (4)

• Excitation spectra of quantum matter without quasiparticles I: Sachdev-Ye-Kitaev models
• Planckian Metal at a Doping-Induced Quantum Critical Point
• Excitation spectra of quantum matter without quasiparticles II: random $t$-$J$ models
• Loop-gas description of the localized-magnon states on the kagome lattice with open boundary conditions

Cited by in corpus (16)

• Sachdev-Ye-Kitaev Models and Beyond: A Window into Non-Fermi Liquids
• Skewed Non-Fermi Liquids and the Seebeck Effect
• Planckian Metal at a Doping-Induced Quantum Critical Point
• Spin liquid to spin glass crossover in the random quantum Heisenberg magnet
• Excitation spectra of quantum matter without quasiparticles II: random $t$-$J$ models
• Small to large Fermi surface transition in a single band model, using randomly coupled ancillas
• A model of randomly-coupled Pauli spins
• Critical metallic phase in the overdoped random $t$-$J$ model
• Competition between spin ordering and superconductivity near the pseudogap boundary in La2-xSrxCuO4: insights from NMR
• Equilibrium dynamics of infinite-range quantum spin glasses in a field
• Thermally enhanced Majorana-mediated spin transport in the Kitaev model
• Thermal Pure States for Systems with Antiunitary Symmetries and Their Tensor Network Representations
• Exact numerical solution of the fully-connected classical and quantum Heisenberg spin glass
• Quasiparticle metamorphosis in the random t-J model
• Dynamic Parallel Spin Stripes from the 1/8 anomaly to the End of Superconductivity in La${}_{1.6-x}$Nd${}_{0.4}$Sr${}_x$CuO${}_4$
• Spin-liquid and spin-glass behavior in quantum spin models with all-to-all p-spin interactions