%0 Journal Article %1 PhysRevLett.128.087201 %A Liu, Zi Hong %A Vojta, Matthias %A Assaad, Fakher F. %A Janssen, Lukas %D 2022 %I American Physical Society %J Phys. Rev. Lett. %K a b %N 8 %P 087201 %R 10.1103/PhysRevLett.128.087201 %T Metallic and deconfined quantum criticality in Dirac systems %U https://link.aps.org/doi/10.1103/PhysRevLett.128.087201 %V 128 %X Motivated by the physics of spin-orbital liquids, we study a model of interacting Dirac fermions on a bilayer honeycomb lattice at half filling, featuring an explicit global SO(3)×U(1) symmetry. Using large-scale auxiliary-field quantum Monte Carlo (QMC) simulations, we locate two zero-temperature phase transitions as function of increasing interaction strength. First, we observe a continuous transition from the weakly interacting semimetal to a different semimetallic phase in which the SO(3) symmetry is spontaneously broken and where two out of three Dirac cones acquire a mass gap. The associated quantum critical point can be understood in terms of a Gross-Neveu-SO(3) theory. Second, we subsequently observe a transition toward an insulating phase in which the SO(3) symmetry is restored and the U(1) symmetry is spontaneously broken. While strongly first order at the mean-field level, the QMC data are consistent with a direct and continuous transition. It is thus a candidate for a new type of deconfined quantum critical point that features gapless fermionic degrees of freedom.

@article{PhysRevLett.128.087201, abstract = {Motivated by the physics of spin-orbital liquids, we study a model of interacting Dirac fermions on a bilayer honeycomb lattice at half filling, featuring an explicit global SO(3)×U(1) symmetry. Using large-scale auxiliary-field quantum Monte Carlo (QMC) simulations, we locate two zero-temperature phase transitions as function of increasing interaction strength. First, we observe a continuous transition from the weakly interacting semimetal to a different semimetallic phase in which the SO(3) symmetry is spontaneously broken and where two out of three Dirac cones acquire a mass gap. The associated quantum critical point can be understood in terms of a Gross-Neveu-SO(3) theory. Second, we subsequently observe a transition toward an insulating phase in which the SO(3) symmetry is restored and the U(1) symmetry is spontaneously broken. While strongly first order at the mean-field level, the QMC data are consistent with a direct and continuous transition. It is thus a candidate for a new type of deconfined quantum critical point that features gapless fermionic degrees of freedom.}, added-at = {2022-03-14T21:44:45.000+0100}, author = {Liu, Zi Hong and Vojta, Matthias and Assaad, Fakher F. and Janssen, Lukas}, biburl = {https://www.bibsonomy.org/bibtex/2445809f9e260a78831ef4054545d9e70/ctqmat}, day = 23, description = {Phys. Rev. Lett. 128, 087201 (2022) - Metallic and Deconfined Quantum Criticality in Dirac Systems}, doi = {10.1103/PhysRevLett.128.087201}, interhash = {69a50081ca4131ec8460475316e78fbe}, intrahash = {445809f9e260a78831ef4054545d9e70}, journal = {Phys. Rev. Lett.}, keywords = {a b}, month = {02}, number = 8, numpages = {6}, pages = 087201, publisher = {American Physical Society}, timestamp = {2023-03-22T11:51:04.000+0100}, title = {Metallic and deconfined quantum criticality in Dirac systems}, url = {https://link.aps.org/doi/10.1103/PhysRevLett.128.087201}, volume = 128, year = 2022 }