Deconfined critical point in a doped random quantum Heisenberg magnet

Darshan G. Joshi , Chenyuan Li , Grigory Tarnopolsky , Antoine Georges (1, 2) , Subir Sachdev

1 CPHT - Centre de Physique Théorique [Palaiseau]
2 Collège de France - Chaire Physique de la matière condensée (A. Georges)

We describe the phase diagram of electrons on a fully connected lattice with random hopping, subject to a random Heisenberg spin exchange interaction between any pair of sites and a constraint of no double occupancy. A perturbative renormalization group analysis yields a critical point with fractionalized excitations at a nonzero critical value pc of the hole doping p away from the half-filled insulator. We compute the renormalization group to two loops, but some exponents are obtained to all loop order. We argue that the critical point pc is flanked by confining phases: a disordered Fermi liquid with carrier density 1+p for p>pc and a metallic spin glass with carrier density p for p

Mots clés: spin: exchange; spin: symmetry; spin: glass; excited state: fractional; critical phenomena; renormalization group; Heisenberg; density; deconfinement; Fermi liquid; confinement; electron; hopping; lattice; magnet; SU(2); site

Domaines: Physique Générale [physics.gen-ph]; Physique des Hautes Energies - Théorie [hep-th]

Darshan G. Joshi, Chenyuan Li, Grigory Tarnopolsky, Antoine Georges, Subir Sachdev. Deconfined critical point in a doped random quantum Heisenberg magnet. Phys.Rev.X, 2020, 10 (2), pp.021033. ⟨10.1103/PhysRevX.10.021033⟩. ⟨hal-02447828⟩