Quantum normal-to-inhomogeneous superconductor phase transition in nearly two-dimensional metals

摘要: In multi-band systems, electrons from different orbitals coexist at the Fermi surface. An attractive interaction among these quasi-particles gives rise to inter-band or hybrid pairs which eventually condense in a superconducting state. These have natural mismatch of their wave-vectors, $\delta k_F$, depends on strength hybridization between orbitals. The existence this scale suggests possibility inhomogeneous ground states even absence an applied magnetic field. Furthermore, since $V$ pressure, provides external parameter control wave-vectors work, we study phase diagram two-dimensional, two-band metal with pairing. We show that as two bands is reduced, system presents normal-to-inhomogeneous superconductor quantum transition critical value $V_c=\Delta_0$. state for $V