Ground state manipulation of atomic waveguide by a giant atom

Abstract In this paper, we study the ground state of a Rydberg atomic waveguide, which is coupled to a giant atom nonlocally via two or multiple sites. This many body system undergoes the degeneracy broken or energy level anti-crossing, depending on the parity of the size of the giant atom and the detuning between the atomic transition frequency and that of the driving field. Together with manipulation of the energy gap, we further show the interesting alternative atomic magnetization in the waveguide and the simultaneous suppression of the atomic magnetization and enhancement of atomic correlation.