Charge-density wave and quantum fluctuations in a molecular crystal

Article

关键词: HOLSTEIN MODEL;    PHASE-TRANSITIONS;    PEIERLS INSTABILITY;    FLUX PHASE;    SYSTEMS;    POLYACETYLENE;   

DOI  :  10.1103/PhysRevB.60.13484

来源: SCIE

【 摘 要 】

We consider an electron-phonon system in two and three dimensions on square, hexagonal, and cultic lattices. The model is a modification of the standard Holstein model where the optical branch is appropriately curved in order to have a reflection positive Hamiltonian. Using infrared bounds together with a recent result on the coexistence of tong-range order for electron and phonon fields, we prove that, at sufficiently low temperatures and sufficiently strong electron-phonon coupling, there is a Peierls instability towards a period two charge-density wave at half-filling. Our results tate into account the quantum fluctuations of the elastic held in a rigorous way and are therefore independent of any adiabatic approximation. The strong coupling and low-temperature regime found here is independent of the strength of the quantum fluctuations of the elastic field. [S0163-1829(99)05543-5].

【 授权许可】

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