Theoretical design of single-molecule NOR and XNOR logic gates by using transition metal dibenzotetraaza[14]annulenes*

Abstract

The idea of replacing traditional silicon-based electronic components with the ones assembled by organic molecules to further scale down the electric circuits has been attracting extensive research focuses. Among the molecularly assembled components, the design of molecular logic gates with simple structure and high Boolean computing speed remains a great challenge. Here, by using the state-of-the-art nonequilibrium Green’s function theory in conjugation with first-principles method, the spin transport properties of single-molecule junctions comprised of two serially connected transition metal dibenzotetraaza[14]annulenes (TM(DBTAA), TM = Fe, Co) sandwiched between two single-walled carbon nanotube electrodes are theoretically investigated. The numerical results show a close dependence of the spin-resolved current-voltage characteristics on spin configurations between the left and right molecular kernels and the kind of TM atom in TM(DBTAA) molecule. By taking advantage of spin degree of freedom of electrons, NOR or XNOR Boolean logic gates can be realized in Fe(DBTAA) and Co(DBTAA) junctions depending on the definitions of input and output signals. This work proposes a new kind of molecular logic gates and hence is helpful for further miniaturization of the electric circuits.

Covalent coupling of DNA bases with graphene nanoribbon electrodes: Negative differential resistance, rectifying, and thermoelectric performance*

“…Since the experiment shows that the current-voltage characteristics have been measured as being stable at room temperature, [37] the optimized structures in our calculations should also reach a stable state at room temperature. [48][49][50][51][52][53] Furthermore, another two interesting effects ca also be observed from these I-V curves: (i) Rectifying effect. The rectification ratio is defined as RR = I(−V )/I(V ), where I(−V ) and I(V ) correspond to the currents under negative and positive biases with the same voltage magnitude.…”

Highly interface-dependent spin transport in an Fe–Mn(DBTAA)–Fe single molecule spintronic device

“…22 Besides, researchers have theoretically studied the spin transport properties of several transition metal dibenzotetraaza[14]annulenes sandwiched between nonmagnetic gold, graphene or carbon nanotube electrodes, and found that perfect spin filtering can be obtained when Fe- and Co(DBTAA) molecules are used. 23–25 In this study, by employing magnetic Fe electrodes and the magnetic Mn(DBTAA) molecule, we focus on exploring the influence of interface structures on magnetic and electronic couplings between the Fe electrode and the Mn(DBTAA) molecule, and the subsequent spin transport behaviours. The results reveal that the interface structures can modulate and even reverse the spin polarization of tunneling electrons over a wide range.…”

Theoretical design of thermal spin molecular logic gates by using a combinational molecular junction

“…In recent years, the design and manufacturing of spin molecular devices being able to perform specific logical functions has attracted ever-increasing attention owing to the rapid development of molecular spintronics. [1][2][3][4] In these socalled spin molecular logic gates, magnetic molecular materials can switch among different states under the action of one or more input signals, and such transition leads to a single logical output signal. Evidently, selection of appropriate magnetic molecular materials becomes a key fac-tor to construct spin molecular logic gates.…”