Electronic conduction through quantum dots undergoing Jahn-Teller transition

Electronic conduction through quantum dots undergoing Jahn-Teller distortion is studied utilizing a model presented recently in connection with investigation of possible magnetovoltaic effect in this system. The quantum dot connected to two metallic leads is described by the single impurity Anderson model (SIAM) Hamiltonian along with two additional terms describing the Jahn-Teller distortion and an applied magnetic field. The self-consistent calculation shows that the Jahn-Teller (J-T) order parameter which is a measure of the splitting of the degenerate dot level is maximum at zero temperature and smoothly goes to zero at the structural transition temperature, Ts. The conductance is greatly suppressed by the J-T distortion at low temperatures, slowly increases and attains a maximum at Ts, above which it shows a slow decrease. When plotted as a function of the energy of the dot level, the conductance shows two peaks corresponding to the two split J-T levels at temperatures below Ts, which further develops into a four peak structure in the presence of a magnetic field.