Error-correcting quantum control for quantum-based technologies
Abstract
Project Abstract: Error-correcting quantum control for quantum-based technologiesHarnessing the power of quantum mechanics and integrating it into novel technologies capable ofperforming tasks far beyond present-day means is a formidable and long-standing goal in the fieldsof quantum information and quantum sensing. Realizing these technologies requires the ability tocontrol microscopic qu"antum systems with unprecedented accuracy. This task is challengingbecause the system interacts with its environment, leading to fl"uctuations in the system~s propertiesand ultimately to decoherence---the loss of information stored in the system. Since someinter"action with the environment is necessary in order to manipulate and measure the system,overcoming these problems requires advances" in the development of control protocols that drivethe system coherently while simultaneously mitigating the deleterious effects of the environment.The fact that it is possible to drive a system with external control pulses that are engineered toproduce an auto"matic self-cancellation of errors due to the environment or driving imperfections,without the need for a precise knowledge of these"" errors, was discovered several decades ago inthe context of nuclear magnetic resonance. However, these approaches, known as dynami""caldecoupling, are largely based on idealized pulse waveforms such as delta-functions and squarepulses. This is often problematic" for their implementation in many quantum-based technologiessince these idealized waveforms cannot be generated with the necessary" speed and precision inreal experimental systems evolving on nanosecond timescales. Moreover, restricting to the use ofonly a few" specialized pulse shapes leads to unnecessarily long pulse sequences which quickly runup against time limitations set by excited s"tate relaxation, phonon excitation, or photon losses.The proposed research aims to drastically reduce the decoherence problem by bu"ilding on recentbreakthroughs developed by the PI to greatly expand the scope of robust quantum control. The PIintroduced a partial reverse-engineering technique to analytically solve the time-dependentSchr~dinger equation for a two-level system in full general"ity, producing an unlimited number ofdriving fields that are smooth and experimentally feasible. This new method for solving the ti"medependentSchr~dinger equation can be combined with concepts from geometry and topology tosystematically construct a general theory of error-correcting quantum control that extends farbeyond traditional dynamical decoupling techniques. These breakthroughs constitute a powerfuladvance of the basic concept of dynamical decoupling that overcomes the limitations arising fromthe use of ideali"zed pulse waveforms. These important results will serve as the starting point forthe proposed research, which aims to achieve simil""ar successes in the context of two-, three-, andmany-level quantum systems simultaneously subject to several time-dependent error s""ources,driving imperfections, and other types of unwanted dynamics. The techniques that will bedeveloped will apply to a broad ran""ge of physical systems, including trapped ions, superconductingcircuits, atomic defect centers, and other solid state spin qubits," and will be compatible withexisting experimental methods for controlling these systems.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Sep 29, 2017
- Source ID
- N000141712971
Entities
People
- Edwin Barnes
Organizations
- Office of Naval Research
- United States Navy
- Virginia Tech