2026/07/31 by Chuang Chen, Subir Sachdev, Zi Yang Meng · 1 citation
Physics and Astronomy · #cond-mat.str-el
16 pages, 7 figures
arxiv created 2026/08/06 · arxiv updated 2026/08/07
We present a quantum Monte Carlo study of the transition between the insulating Néel state and the nodal d-wave superconductor on the square lattice at half-filling. We access a regime of frustrated magnetic order without a sign problem using a parton representation of the electron in terms of fermionic spinons and bosonic chargons. Both partons move in a background π-flux (so the electron experiences no net flux) and are coupled to a quantum fluctuating SU(2) lattice gauge field. In contrast to earlier studies directly on the electronic degrees of freedom, we find evidence for a second-order deconfined quantum phase transition at which both the Néel and d-wave superconductivity orders vanish continuously. We compute correlators of the spinon-chargon composite with the same quantum numbers as the electron: we find a gapless Dirac dispersion inside the d-wave superconductor, turning into a gapped dispersion in the antiferromagnet.