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Mardi 16 avril 2019 - 14:00

Large QHC logic gate design

Omid Faizy (LPT Toulouse)

par Revaz Ramazashvili - 16 avril 2019

After the seminal work of A. Aviram and M. Ratner [1], a few hybrid molecular electronic circuits have been proposed for molecular electronics [2]. The semi-classical mono-molecular approach was then introduced [3], where the entire arithmetic and logic unit (ALU) of a calculator was proposed to be embedded in a single very large molecule (Y. Wada proposed the same with electronic circuits to be constructed atom by atom on a surface [4]). A more chemically realistic single-molecule 2-digit full adder was proposed by J. Ellenbogen [5].

To avoid copying the electronic circuit architecture to design such molecular ALU, a new quantum control protocol, called the Quantum Hamiltonian Computing approach (QHC), was proposed in 2005 [6]. It does not involve dividing the molecular structure into individual elementary gates (or switches or transistor or qubits) and still belongs to the same family of control theory than the one generally applied to quantum computer.

Following this new QHC approach, 2-inputs/1-output (OR, NOR, AND, NAND, XOR, NXOR) QHC Boolean logic gates were designed [7] opening the experimental realization of molecule logic gate using starphene molecules like the recent NAND gate [8,9]. We will recall the basic of the QHC design to reach single-molecule logic gate chemical structures and will present our new approach for larger QHC gates like the 2-inputs/2-outputs half adder and 3-input/2-output full adder within two different output reading protocols.

[1]. A. Aviram, M.A. Ratner, Chem. Phys. Lett. 29 (1974) 277.

[2]. C. Joachim, J.K. Gimzewski, A. Aviram, Nature, 408, 541 (2000).

[3]. F.L. Carter, Physica D, 10, 175 (1984).

[4]. Y. Wada, T. Uda, M. Lutwyche, S. Kondo, S. Heike, J. Appl. Phys. 74, 7321 (1993).

[5]. J.C. Ellenbogen and J.C. Love, Proc. IEEE, 88, 386 (2000)

[6] .I. Duchemin and C. Joachim, Chem. Phys. Lett., 406, 167 (2005).

[7] N. Renaud and C. Joachim, Phys. Rev. A, (2008), 78, 062316.

[8] W. H. Soe et al ; Phys. Rev. B : Condens. Matter, (2011), 83, 155443.

[9] D. Skidin ; et al, ACS Nano 12 (2), 1139-1145 (2018).

Post-scriptum :

contact : R. Ramazashvili