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arXiv · 1011.1993

Gradient Catastrophe and Fermi Edge Resonances in Fermi Gas

Eldad Bettelheim·Yitzhak Kaplan·Paul B. Wiegmann
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Abstract

A smooth spatial disturbance of the Fermi surface in a Fermi gas inevitably becomes sharp. This phenomenon, called {\it the gradient catastrophe}, causes the breakdown of a Fermi sea to disconnected parts with multiple Fermi points. We study how the gradient catastrophe effects probing the Fermi system via a Fermi edge singularity measurement. We show that the gradient catastrophe transforms the single-peaked Fermi-edge singularity of the tunneling (or absorption) spectrum to a set of multiple asymmetric singular resonances. Also we gave a mathematical formulation of FES as a matrix Riemann-Hilbert problem.

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Eldad Bettelheim, Yitzhak Kaplan, Paul B. Wiegmann. 2011-03-23. Gradient Catastrophe and Fermi Edge Resonances in Fermi Gas. https://doi.org/10.1103/physrevlett.106.166804

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