Abstract
We show that the fermionic and bosonic spectrum of fermions at finite density coupled to a critical boson can be determined nonperturbatively in the combined limit with fixed. In this double scaling limit, the boson two-point function is corrected but only at one loop. This double scaling limit therefore incorporates the leading effect of Landau damping. The fermion two-point function is determined analytically in real space and numerically in (Euclidean) momentum space. The resulting spectrum is discontinuously connected to the quenched result. For with fixed the spectrum exhibits the distinct non-Fermi-liquid behavior previously surmised from the RPA approximation. However, the exact answer obtained here shows that the RPA result does not fully capture the IR of the theory.
3 More- Received 20 December 2016
DOI:https://doi.org/10.1103/PhysRevB.96.155125
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