ITR: Molecular Qubit Transformations with Phase-Shaped Femtosecond Pulses

University Of California-Berkeley, Berkeley CA

Investigators

Abstract

In this ITR-Small project funded by the Chemistry Division, Stephen Leone of the University of California-Berkeley will investigate single and multiple qubit operations on pairs of superposition states formed among rotational, vibrational, and electronic degrees of freedom in diatomic molecules. Using multiple pulse sequences from ultrafast lasers, phase and amplitude pulse shaping, and evolutionary algorithms, optimal pulses will be determined for single qubit transformations in molecules, such as Z-gates and Hadamard transformations. The work is further extended to multiple qubit operations such as controlled-Z and swap gates. Lithium dimers will be used as the molecular system for these studies. The experiments in this project will address for the first time the use of molecular rotational states as a motional control qubit for controlled transformations of an electronic qubit. This project focuses on exploring logic gates that may be useful for constructing a quantum computer. In the course of this research students will receive training in quantum mechanics and the use of ultrafast lasers and pulse shaping. Since these areas are already of great relevance to optical communications and optical computing efforts, the students will experience the integration of basic science and its applications in advanced information technology applications. In addition, what is learned from molecular systems may enable the formation of qutrits (three-level systems) and multi-qubits (superpositions of many levels at a time) that will broaden thinking about potential algorithms for quantum information processing. This research has other possible applications to areas such as quantum cryptography and code-breaking, information storage and retrieval, and faster processing with quantum computing. Fields affected include fiber optic communications, information transmission, and data encryption.