Inhomogeneous superconducting state in quasi-one-dimensional systems

We report on results of theoretical study of nonuniform superconducting states in quasi-one-dimensional systems, with attractive interactions and Zeeman splitting between electron spins. Using bosonization to treat intrachain electron-electron interactions, and a combination of renormalization group and mean-field approximation to tackle interchain couplings, we obtain the phase diagram of the system, and show that the transition between the uniform and nonuniform superconducting phases is a continuous transition of the commensurate-incommensurate type.