Quarks and Compact Stars (QCS)
Oct. 20-22, 2014, KIAA at Peking University, Beijing - P. R. China

Spontaneous magnetization of quark matter in the inhomogeneous chiral phase

Ryo Yoshiike

Kyoto University

Abstract: Recently, a new phase which appears around the conventional chiral transition line in QCD phase diagram has been found in mean field approximation of the NJL model [1]. In this phase, chiral symmetry is broken with the periodically modulating chiral condensate. Here we consider formation of static scalar and pseudoscalar density wave condensates on the chiral circle called gdual chiral density wave (DCDW)h. We study the response of quark matter to a weak external magnetic field to show the spontaneous magnetization in the DCDW phase. In an external magnetic field, the energy spectrum of the lowest Landau level becomes asymmetric about zero and chiral anomaly manifests through [2]. This spectral asymmetry contributes to the thermodynamic potential by the term proportional to a magnetic field, which is the origin of the spontaneous magnetization in the DCDW phase. Furthermore, using the generalized Ginzburg-Landau expansion [3], we expand the thermodynamic potential in an external magnetic field and discuss the critical exponent of the magnetic susceptibility around the Lifshitz point.
References
[1] E. Nakano, T. Tatsumi, Phys. Rev. D 71, 114006 (2005)
[2] T. Tatsumi, K. Nishiyama, S. Karasawa, arXiv:1405.2155
[3] D. Nickel, Phys. Rev. Let. 103, 072301 (2009)