Bi-stability in single impurity Anderson model with strong electron–phonon interaction(polaron regime)

Abstract

a b s t r a c tWe consider a single impurity Anderson model (SIAM) in which the quantum dot(QD) is strongly coupled to a phonon bath in polaron regime. This coupling results in an effective e-e attraction. By computing the self energies using a current conserving approximation which is up to second order in this effective attraction, we show that if the interaction is strong enough, in non particle-hole (PH) symmetric case, the system would be bi-stable and we have hysteresis loop in the I-V characteristic. Moreover, the system shows negative differential conductance in some bias voltage intervals.

Light Induced Negative Differential Conductance in Molecular Junctions: Role of Triplet States and Electron-Phonon Interaction

“…At molecular scales the interaction of electrons with the quantum of the vibrational modes, the so called phonons, plays an important role in determining the transport properties. Several novel phenomena including negative differential conductance (NDC), dynamical switching and current hysteresis [11,12,13,14,15], are believed to originate from electronphonon (e-ph) interaction [16,17,18,19].…”

Interplay of electron-electron and electron-phonon interactions in molecular junctions

“…One of the main characteristics of MJs in comparison to large QDs is the strong coupling of electrons to the vibrations of molecule. This electron-phonon (e-ph) interaction is one of the most important candidates to theoretically explain NDC [15,16,17]. On the other hand, Coulomb interaction can also be the origin of NDC in some systems where the LUMO and HOMO levels have different couplings to the leads [18].…”