Molecular electronic logic circuit

Keywords Intramolecular kirchhoff laws Molecular electronics Molecular logic gates Single molecule electronic circuits Quantum hamiltonian computing... 

At the moment molecular electronic circuits and logic devices are still some distance away, but the building blocks are there and the tools are being assembled. 

Molecular electronics (ME) is so named because it uses molecules to function as switches and wires . ME is a term that refers both to the use of molecular materials in electronics and to electronics at molecular level. It is as yet not very clear how molecular electronic devices will operate, but it is conjectured that active molecules are needed, either in isolation or becoming active by association with other molecules. It is thought that electronics is likely to imitate some of the basic functions of macroscopic devices such as memories, sensors and logic circuits. 

Organic Field Effect Transistors/Molecular Electronics. Organic field effect transistors (OFETS) and molecular electronics are two areas of intensive research for both academic and industrial institutions (346). The extensive research on these devices stems from their ability to be processed at low temperatures and from their compatibility with plastic substrates. Several applications of OFETs have been proposed, including smart cards (347), active matrix displays (348), and logic circuits (349). Both polymeric and oligomeric materials have been studied for use in OFETs because the properties can be tailored to vary the HOMO-LUMO gap physical characteristics such as mechanical flexibility and processability are also advantageous (350). 

The interest in interference effects in cross-conjugated molecules arose from molecular electronics. The chemist s vision of molecular electronics consists of chemically tailored circuits, where the electronic function is controlled by carefully designed substituents. This requires more than molecular wires it requires functions such as memory elements, switches, logic elements, and gate dielectrics. In short, it requires polarizable but nonconducting elements. In many of these cases, an ofT state is required in addition to the on state. Sometimes there is a requirement for fast switching between these states, and at other times long-term stability of either the on or oflT state is needed. 

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