Collaborative Research: Quantum Control of Qudits and Quantum Transport in Optical Lattics

University Of New Mexico, Albuquerque NM

Investigators

Abstract

This NSF award will support the development of general methods to control and measure physical systems whose behavior is governed by quantum mechanics. As a concrete physical testbed the project will use cold atoms and optical lattices (spatially periodic potential wells formed by interfering laser beams used to trap cold atoms). This system provides access to a broad range of quantum phenomena, and is considered one of the leading platforms for quantum information science such as quantum computation. The immediate goal is to develop robust and flexible control tools to manipulate quantum information encoded in finite sets of atomic ground states (qudits). By correlating the state of an atom with its position in an optical lattice, it becomes possible to control the quantum mechanical motion of atoms on a grid. Simultaneous quantum control of the internal and motional quantum states of atoms will be essential if the atom-lattice system is to be used for quantum computation and quantum simulation of condensed-matter physics, both of which are grand challenges pursued by research groups across the world. When physical devices are used to perform real world tasks, the process can be understood abstractly in terms of a system moving through a sequence of configurations (states) in response to external commands (controls). In practice, control of the device must be accurate and reliable even in the presence of errors and imperfections. This is a non-trivial challenge even for systems governed by classical mechanics, and has historically given rise to an entire engineering discipline known as Control Science. Modern advances in nanoscience is pushing technology into the quantum realm, and an analogous new field of Quantum Control must therefore be established. This NSF award will contribute substantially to the knowledge base of Quantum Control and Quantum Information Science. Notably, the tools and techniques developed for the cold atoms and optical lattice platform will be broadly applicable because a single set of mathematical principles underlie the design of controls for any quantum system, be it atomic, molecular, optical or condensed matter. All aspects of the research will involve graduate students, and will occur within the framework of the Center for Quantum Information and Control (CQuIC), a newly established joint venture involving principal investigators at the University of New Mexico and the University of Arizona. The award will thus contribute to the training of future scientists and researchers in Quantum Control and Quantum Information Science.