In this paper we investigate the phase structure of a ($1+1$)-dimensional quark model with four-quark interaction and in the presence of baryon (${\mu }_B$), isospin (${\mu }_I$), and chiral isospin (${\mu }_{I5}$) chemical potentials. Spatially inhomogeneous chiral density wave (for chiral condensate) and single wave (for charged pion condensate) approaches are used. It is established that in the large-$N_c$ limit ($N_c$ is the number of colored quarks) there exists a duality correspondence between the chiral symmetry breaking phase and the charged pion condensation (PC) one. Moreover, it is shown that inhomogeneous charged PC phase with nonzero baryon density is induced in the model by arbitrary small values of the chemical potential ${\mu }_{I5}$ (for a rather large region of ${\mu }_B$ and ${\mu }_I$).

• Received 8 April 2017

DOI:https://doi.org/10.1103/PhysRevD.95.105010