2011/04/07 by S. Prem Kumar
Physics and Astronomy · #Black Holes and Theoretical Physics #Fermion #Instability #Massless particle #Mathematical physics #Pairing #Particle physics theoretical and experimental studies #Physics #Quantum Chromodynamics and Particle Interactions #Quantum electrodynamics #Quantum mechanics #hep-th
paper · pdf · doi:10.1103/physrevd.84.026003
published as Phys.Rev.D84:026003,2011 · 44 pages, 10 figures, uses latex
arxiv created 2011/04/07 · openalex publication_date 2011/07/15 · arxiv updated 2015/03/18 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We consider probe Dp-branes, p=3, 5, 7, in global AdS5\ifmmode×\else\texttimes\fiS5, rotating along an internal direction in the S5. These are dual to strongly interacting N=4 super Yang-Mills on S3 with massless fundamental flavors, in the presence of an R-symmetry chemical potential for flavor fermions. For massless, ``anti de Sitter-filling'' Dp-brane embeddings at zero temperature, we find an infinite set of threshold values of the chemical potential at which instabilities are triggered. The onset of instability is always preceded by metastability of the zero-density state. From the onset values of the chemical potential, we infer that unstable directions favor a homogeneous condensate of a bilinear made from fermion harmonics, or Cooper pairing. We confirm this picture both numerically and analytically. The linearized analysis showing the appearance of instabilities involves a charged scalar in global anti de Sitter space coupled to a (large) constant background gauge potential. The resulting frequency space correlator of the fermion bilinear at strong coupling displays poles in the upper half plane. In contrast, the correlator at zero coupling exhibits Pauli blocking due to occupation of states below the Fermi level, but no instabilities. The end point of the strong coupling instability is not visible in our setup.