Cooper Pairing in Non-Fermi Liquids
Figure 1: Top: conventional phase diagram of a quantum critical point (QCP) associated with an order parameter ϕ, with a superconducting dome (SC) partially overlapping the quantum critical region of the "bare" QCP of a metal. Bottom: the phase diagram obtained in this paper, with the SC dome fully overlapping the incipient regime of incoherent fermionic quasiparticles, while the quantum critical ϕ fluctuations survive into higher temperatures in the normal state. [©2015 American Physical Society]
Whether the non-Fermi-liquid behavior of fermionic systems, developing in the proximity of a quantum critical point, is stable or not toward the formation of Cooper pairs is a challenging open question in the physics of strongly correlated systems. In a new, editor-suggested, article in Physical Review B, Prof. Subir Sachdev and colleagues from UC Santa Barbara, Caltech, and MIT study systems where the non-Fermi-liquid behavior arises as a result of the interaction of a gapless bosonic mode with fermions in the vicinity of the Fermi surface.
See M.A. Metlitski, D. F. Mross, S. Sachdev, and T. Senthil, "Cooper pairing in non-Fermi liquids" Physical Review B 91 (4 March 2015) | doi: http://dx.doi.org/10.1103/PhysRevB.91.115111.