Comparison of variational and CSE methods to polaron ground-state energy
نویسندگان
چکیده
Taking the same trial wave function, the ground-state energy of Fröhlich polaron is investigated by variational method and coherent-state expansion (CSE) one, respectively. Within the accuracy to α2(the electron-phonon coupling constant), both methods can give the same analytic expressions of polaron groundstate energy as the function of electron-phonon coupling constant. We find that the CSE method can much simplify the calculation and shows more advantages in higher order approximations. PACS numbers: 71.38.-k, 63.20.Kr, 31.15.-p
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تاریخ انتشار 2008