Chiral anomaly induces superconducting baryon crystal

Journal of High Energy Physics

Regular Article - Theoretical Physics

Andreas Schmitt¹  Geraint W. Evans¹ 

[1] Mathematical Sciences and STAG Research Centre, University of Southampton, Highfield Campus, SO17 1BJ, Southampton, United Kingdom;

关键词: Chiral Lagrangian;    Phase Diagram or Equation of State;    Effective Field Theories;   

DOI  :  10.1007/JHEP09(2022)192

 received in 2022-06-09, accepted in 2022-08-09,  发布年份 2022

来源: Springer

【 摘 要 】

It was previously shown within chiral perturbation theory that the ground state of QCD in a sufficiently large magnetic field and at nonvanishing, but not too large, baryon chemical potential is a so-called chiral soliton lattice. The crucial ingredient of this observation was the chiral anomaly in the form of a Wess-Zumino-Witten term, which couples the baryon chemical potential to the magnetic field and the gradient of the neutral pion field. It was also shown that the chiral soliton lattice becomes unstable towards charged pion condensation at larger magnetic fields. We point out that this instability bears a striking resemblance to the second critical magnetic field of a type-II superconductor, however with the superconducting phase appearing upon increasing the magnetic field. The resulting phase has a periodically varying charged pion condensate that coexists with a neutral pion supercurrent. We construct this phase analytically in the chiral limit and show that it is energetically preferred. Just like an ordinary type-II superconductor, it exhibits a hexagonal array of magnetic flux tubes, and, due to the chiral anomaly, a spatially oscillating baryon number of the same crystalline structure.

【 授权许可】

Unknown   
© The Author(s) 2022