title: Controlled full adder-subtractor by vibrational computing.
abstract: The implementation of a quantum-controlled full adder-subtractor of two binary digits and of a "carry in" or a "borrow in" is simulated by encoding four qubits in the vibrational eigenstates of a tetra-atomic molecule (trans-HONO). The laser field of the gate is computed using optimal control theory by treating dynamics in full dimensionality. A controlled qubit enforces the addition or the subtraction. The global unitary transformation that connects the inputs to the outputs is driven by a single laser pulse. This decreases the duration of the operation and allows for a better use of the optical resources and for an improvement of the fidelity (>97%). Initialization and reading out are discussed. The timescale of the sequence initialization, gate and read out is<100 ps.
authors.affiliation: Laboratoire de Chimie Physique, Université de Paris-Sud, UMR8000, Orsay, F-91405, France.
authors.forename: Laëtitia
authors.initials: L
authors.lastname: Bomble
authors.forename: David
authors.initials: D
authors.lastname: Lauvergnat
authors.forename: Françoise
authors.initials: F
authors.lastname: Remacle
authors.forename: Michèle
authors.initials: M
authors.lastname: Desouter-Lecomte