The ground-state energy and effective mass of a polaron in the conduction band of a narrow-gap, weak-coupling semiconductor are calculated by diagonalizing a 4×4 matrix Hamiltonian to the required order of accuracy. Much smaller corrections to the simple Fröhlich theory are found than have been reported by Das Sarma and Mason. An explanation for the discrepancy is proposed.

• Received 27 January 1986

DOI:https://doi.org/10.1103/PhysRevB.34.5927