Ground-State Properties of Möbius Conjugated Polymers: The Role of Interchain Coupling and System Size

We present a theoretical study of the ground-state properties of Möbius conjugated polymers using the tight-binding model, with particular emphasis on how interchain coupling and system size affect the system's behavior. Two distinct dimerization lattice configurations, columnar and staggered phases, are examined. Unlike periodic boundary conditions, which invariably stabilize a ground state with staggered dimerization, Möbius boundary conditions give rise to a quantum phase transition. Under weak interchain coupling, the ground state of the system exhibits columnar dimerization, while under stronger coupling, staggered dimerization dominates. This phenomenon becomes increasingly pronounced with decreasing system size. In particular, we observe the formation of a soliton-antisoliton pair in the staggered dimerization phase.