Soluble fermionic quantum critical point in two dimensions

@article{Ray2020SolubleFQ,
  title={Soluble fermionic quantum critical point in two dimensions},
  author={Shouryya Ray and Matthias Vojta and Lukas Janssen},
  journal={Physical Review B},
  year={2020},
  volume={102}
}
We study a 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 $\eta_\phi = 2$, the correlation length and the… 
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