Sikarin Yoo-Kong. Large polaron mobility in a magnetic field of arbitrary strength . Master's Degree(Physics). Mahidol University. : Mahidol University, 2005.
Large polaron mobility in a magnetic field of arbitrary strength
Abstract:
This research was done in the three stages. In the first stage, the propagator
was obtained for a charged particle subjected to an electromagnetic field and being
under the influence of a non-local oscillator. The method of derivation was based on
a direct solution of the corresponding classical equation of motion.
In the second stage, an analytic expression of the ground state energy of the
polaron in a magnetic field was derived by J.D. Devreese and F. Brosens but no
numerical data was presented. So, the objective of this stage was to present some
numerical results.
Finally, the steady-state condition of an electron interacting with the phonons
of a crystal in finite electric and constant magnetic fields was determined via two
methods utilizing Feynman path integrals. The first method was called “Double Path”.
The second method was called “Single Path”. The loss rate of momentum when
applying fields was expressed in a form in which the lattice coordinates had been
eliminated exactly by path integrals methods. The quadratic influence functional
used to simulate the electron-lattice interaction was shown to be derived from a selfconsistent
relation for the impedance tensor. The Feynman one-oscillator model is
discussed in terms of the self-consistency relation. The applied magnetic and electric
fields problem is discussed. Lastly, we have derived the explicit form of the effective
mass and the mobility of the polaron in a magnetic field