ITR: Molecular Qubit Transformations with Phase-Shaped Femtosecond Pulses

在这个由化学部门资助的ITR-Small项目中，加州大学伯克利分校的Stephen Leone将研究双原子分子中旋转、振动和电子自由度之间形成的叠加态对上的单和多量子位操作。使用来自超快激光的多个脉冲序列，相位和幅度脉冲整形以及进化算法，将确定分子中单量子位变换的最佳脉冲，例如z门和哈达玛变换。这项工作进一步扩展到多量子位操作，如控制z和交换门。锂二聚体将作为这些研究的分子体系。该项目的实验将首次解决使用分子旋转状态作为电子量子位控制转换的运动控制量子位。这个项目的重点是探索可能对构建量子计算机有用的逻辑门。在这项研究的过程中，学生将接受量子力学和使用超快激光和脉冲整形的训练。由于这些领域已经与光通信和光计算的努力有很大的相关性，学生将体验到基础科学及其在先进信息技术应用中的应用的整合。此外，从分子系统中学到的东西可能会形成量子位（三能级系统）和多量子位（一次多个能级的叠加），这将扩大对量子信息处理潜在算法的思考。这项研究还有其他可能的应用领域，如量子密码学和密码破译，信息存储和检索，以及量子计算的更快处理。受影响的领域包括光纤通信、信息传输和数据加密。

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.