## Abstract

The present work deals with the general polaron theory and, more specifiaclly, with the electrical and optical properties of ionic crystals and polar semiconductors, resulting from the interaction between charge carriers and lattice vibrations.

We have developed a new method based on the resolution of Heisenberg equations of motion for the particule by successive iterations. Two different approaches wer eused according to the value of the coupling constant : the first one holds true only at low couling strengths whereas the second, valid in principle for all strengths , is particularly well adapted for strong coupling.

With these treatments, we have been able to investigate the following interesting points:

1) variation of the effective polaron mass with velocity ; one finds an increase

of mass with velocity which leads to suggest new cyclotron resonance

experiments (possible influence of the electric field on the cyclotron

frequency and anomalous variations of the latter with magnetic field);

2) evaluation of the mobility for high electric fields ; beyond a critical

value there appears a lowering of the mobility by emission of phonons due

Jerenkov like effect ;

3) the absorption of light by free polarons Is treated within the framework

of the Born-Oppenheimer adiabatic approximation.

We have developed a new method based on the resolution of Heisenberg equations of motion for the particule by successive iterations. Two different approaches wer eused according to the value of the coupling constant : the first one holds true only at low couling strengths whereas the second, valid in principle for all strengths , is particularly well adapted for strong coupling.

With these treatments, we have been able to investigate the following interesting points:

1) variation of the effective polaron mass with velocity ; one finds an increase

of mass with velocity which leads to suggest new cyclotron resonance

experiments (possible influence of the electric field on the cyclotron

frequency and anomalous variations of the latter with magnetic field);

2) evaluation of the mobility for high electric fields ; beyond a critical

value there appears a lowering of the mobility by emission of phonons due

Jerenkov like effect ;

3) the absorption of light by free polarons Is treated within the framework

of the Born-Oppenheimer adiabatic approximation.

Original language | English |
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Publisher | SCK CEN |

Number of pages | 175 |

State | Published - Sep 1968 |

Externally published | Yes |

### Publication series

Name | SCK CEN Reports |
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Publisher | SCK CEN |

No. | BLG-436 |