Vibrational State Approach to Quantum Computing

Marquette University, Milwaukee WI

Investigators

Abstract

A theoretical study is proposed of a promising new approach to quantum computing which uses the vibrational eigenstates of molecules to represent quantum bits, and fast femtosecond infrared laser pulses shaped with optimal control to apply quantum logic gates (i.e., to induce specific vibrational transitions). This approach potentially meets all five DiVincenzo criteria for quantum computing and offers the unique possibility of operation on a sub- picosecond time scale. Current experimental techniques use feedback loops to optimize the pulse shape. However, without theoretical guidance, experimentalists are faced with an over-whelmingly large parameter space in which to search for optimal pulse parameters. If pulse parameters are not carefully chosen, the experimental pulse shape optimization procedure may not converge, or it may induce highly undesirable transitions. The objective of this study is to provide crucial theoretical guidance for choosing the various parameters (duration, frequency spectrum, amplitude, etc.) of the shaped pulses. Furthermore, specific molecules which are best for quantum logic operations are unknown and theoretical calculations will help to choose the best candidates for experimental consideration. Preliminary results presented in the proposal demonstrate importance of theoretical studies for further progress in the field, support feasibility of the approach and attest to the ability of the author to conduct the proposed research.