Energy Band Structure of the Electron Gas in Periodic Quantum Wells

The energy band structure and current density of electron gas with an exchange-correlation effect in periodic quantum wells are discussed. It is found that the energy band shows a swallowtail structure at the boundary of the first Brillouin zone when the electron exchange-correlation effect is presented and the average electron density is smaller than a critical value. The energy band structure is closely related to the current density of the system.