The results indicate: the effective mass of an acoustical polaron undergoes a sudden increasing when the e-p coupling constant achieves the critical value and then the self-trapping occurs.

• 结果表明:电子-声子耦合达到一定强度时声学极化子有效质量发生突变而使极化子自陷,声学极化子在二维系统中比三维条件下更容易自陷。