摘要
结合相对运动的近似波函数和修正的Ｌｅｅ（李政道）ＬｏｗＰｉｎｅｓ变分法，研究了二维和三维大双极化子的稳定性．得到了临界耦合参数αｃ和临界介电常数比ηｃ．与近来用完全不同的变分方法求得的结果相一致．还标定了在１／α，η平面上双极化子稳定存在的区域．结果显示。
Abstract The large bipolaron in two and three dimensions is investigated by combining an approximate wave functions for the relative motion and the modified Lee Low Pines variational method. The values of the critical coupling constant α c above which bipolarons may exist and the critical ratio of dielectric constants η c below which bipolarons may exist are evaluated, which are very close to the recent results obtained within a totally different variational approach. In addition, the stability region of bipolarons in the 1/α,η plane is clearly plotted. It is also found that low dimensional materials are more favorable for the formation of bipolarons.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
1998年第2期294-299,共6页
Acta Physica Sinica
