%0 Journal Article %1 PhysRevB.102.081112 %A Ray, Shouryya %A Vojta, Matthias %A Janssen, Lukas %D 2020 %I American Physical Society %J Phys. Rev. B %K a b %N 8 %P 081112 %R 10.1103/PhysRevB.102.081112 %T Soluble fermionic quantum critical point in two dimensions %U https://link.aps.org/doi/10.1103/PhysRevB.102.081112 %V 102 %X We study a particular model for a quantum critical point in two spatial dimensions between a semimetallic phase, characterized by a stable quadratic Fermi node, and an ordered phase, in which the spectrum develops a band gap. The quantum critical behavior can be computed exactly, and we explicitly derive the scaling laws of various observables. While the order-parameter correlation function at criticality satisfies the usual power law with anomalous exponent $\eta_= 2$, the correlation length and the vacuum expectation value of the order parameter exhibit essential singularities upon approaching the quantum critical point from the insulating side, akin to the Berezinskii-Kosterlitz-Thouless transition. On the semimetallic side, the correlation length remains infinite, leading to an emergent scale invariance throughout this phase. The transition may be realized experimentally using ultracold fermionic atoms on optical kagome or checkerboard lattices.

@article{PhysRevB.102.081112, abstract = {We study a particular model for a quantum critical point in two spatial dimensions between a semimetallic phase, characterized by a stable quadratic Fermi node, and an ordered phase, in which the spectrum develops a band gap. The quantum critical behavior can be computed exactly, and we explicitly derive the scaling laws of various observables. While the order-parameter correlation function at criticality satisfies the usual power law with anomalous exponent $\eta_= 2$, the correlation length and the vacuum expectation value of the order parameter exhibit essential singularities upon approaching the quantum critical point from the insulating side, akin to the Berezinskii-Kosterlitz-Thouless transition. On the semimetallic side, the correlation length remains infinite, leading to an emergent scale invariance throughout this phase. The transition may be realized experimentally using ultracold fermionic atoms on optical kagome or checkerboard lattices.}, added-at = {2020-12-18T09:44:13.000+0100}, author = {Ray, Shouryya and Vojta, Matthias and Janssen, Lukas}, biburl = {https://www.bibsonomy.org/bibtex/2fefc12eee5d7634bc1e6899c0d40fd69/ctqmat}, day = 17, description = {Phys. Rev. B 102, 081112(R) (2020) - Soluble fermionic quantum critical point in two dimensions}, doi = {10.1103/PhysRevB.102.081112}, interhash = {9ae2206f137f9a83bf8980639afceedb}, intrahash = {fefc12eee5d7634bc1e6899c0d40fd69}, journal = {Phys. Rev. B}, keywords = {a b}, month = {8}, note = {cite arxiv:2001.09155Comment: 5+7 pages, 3+3 figures}, number = 8, numpages = {6}, pages = 081112, publisher = {American Physical Society}, timestamp = {2023-01-16T14:49:29.000+0100}, title = {Soluble fermionic quantum critical point in two dimensions}, url = {https://link.aps.org/doi/10.1103/PhysRevB.102.081112}, volume = 102, year = 2020 }