This paper reports ground and excited states calculations of dendrimer by a methodology based on INDO/S, including electronic correlation CI. The results reveal the existence of different electronic patterns for the different generations of this molecule. The results indicate that this class of dendrimers has a peculiar behavior on dipole moment of the different families. These results are consistent with recent experimental data supporting the importance of this state for the mechanism of the interaction of dendrimer. The mechanism of relaxation of dendrimer is supported by the absorption spectra simulation and the conclusion comes by analysis of main transitions presents on different generations of this class of molecules.

In this work is presented a theoretical investigation of the neutral and bipolaronlike ground and excited states of molecules and polymers isoelectronic composed by Polyacetylene, Polyazine and Polyazoethene. The results obtained, utilizing DFT and ab initio methodologies, reveal that a very good defects description can be important in the investigation of insulator-metal transition of quasiunidimensional polymers indicating metallic behavior around the Fermi level as mechanism of conductivity of polymers. This result is consistent with experimental data and do not anticipate by Su-Schrieffer-Heeger (SSH) methodology. Our results are consistent with significant features as a nanodevice and can be summarized as: (i) it could be used as single directional molecular rectifier with a conformational geometry with small lead coupling; (ii) our non-equilibrium green function simulation present that Polyacetylene, Polyazine and Polyazoethene could rectified without gate current; (iv) based on properties of bonds type ( / , it can be utilized to design devices with applications in molecular electronics.

In this work we obtain analytically the transport properties as current and conductance in a toy model system formed by a quantum dot with a single level connected to a Kitaev chain deposited on a s-wave superconductor to identify the signature of Majorana zero modes (MZMs) called Majorana Fermions in solid state. For this, we use the Non-Equilibrium Green’s Functions (NEGF) also named as Keldysh formalism in the matrix form to obtain the current–voltage (I–V) and conductance– voltage (G–V) curves to which goes to characterize the investigated system. Thus, it’s possible to verify the presence of the Majorana Fermions in three points: (i) Conductance peak in zero polarization; (ii) The current difference depends on the asymmetry of μL and μR. We find that only for μL = μR, the source and drain currents are equal. (iii) The current difference depends on the asymmetry of ΓL and ΓR.

This work presents an analytical study of electronic transport in dimerized trans-polyacetylene (Trans PA) oligomers containing even (n = 4, 6, 8, 10 sites) and odd (n = 3, 5, 7, 9 sites) chains where the site C 1 is sandwiched by two metallic electrodes (Left and Right). These devices exhibit T-shaped geometry and are investigated by Su-Schrieffer-Heeger (SSH) model via Heisenberg equation of motion combined with the Keldysh formalism. We introduced disorder into the system through the dimerization force (δ) demonstrating that the dimerization in the chain can effectively lead to a linear (low δ) or zigzag (high δ) behavior, besides also suffering increase or decrease in conductance peak [dI/dV]max. The odd chains exhibit trivial topological behavior to which the conductance peaks are suppressed as dimerization disorder is considered-creates barriers for tunneling. On the other hand, we have an opposite behavior for conductance peaks in the even chains. For example, the chain with weak dimerization (low δ) has a perfect transmission for even chains. In addition, we note for odd chains the formation of a plateau in the I–V curve for bias voltages and for even chains that show a linear current. This procedure shows an analytical study through the tunneling of the parameters on the device, such parameters as the tunneling amplitude (Г L/R ) can be accessible experimentally.