Atom matterwave interferometry requires mirror and beam splitter pulses that are robust to inhomogeneities in field intensity, magnetic environment, atom velocity, Zeeman substate. We present theoretical results which show pulse shapes determined using quantum control methods can significantly improve interferometer performance by allowing broader distributions, larger areas, higher contrast. have applied gradient ascent engineering (grape) optimize the design of phase-modulated for a...

Quadratic convergence throughout the active space is achieved for gradient ascent pulse engineering (GRAPE) family of quantum optimal control algorithms. We demonstrate in this communication that Hessian GRAPE fidelity functional unusually cheap, having same asymptotic complexity scaling as itself. This leads to possibility using very efficient numerical optimization techniques. In particular, Newton-Raphson method with a rational function (RFO) regularized shown work require fewer system...

Auxiliary matrix exponential method is used to derive simple and numerically efficient general expressions for the following, historically rather cumbersome, hard compute, theoretical methods: (1) average Hamiltonian theory following interaction representation transformations; (2) Bloch-Redfield-Wangsness of nuclear electron relaxation; (3) gradient ascent pulse engineering version quantum optimal control theory. In context spin dynamics, auxiliary more than methods based on factorizations...

We present optimal control methods for the optimization of periodic pulsed dynamic nuclear polarization (DNP) sequences. Specifically, we address challenge a basic and repeated pulse sequence element which, apart from being easily adaptable to spin systems with different coupling interaction sizes, also proves beneficial in terms performance. It is demonstrated that matrix power logarithm functions combined an auxiliary formalism can be used derive expressions gradient ascent engineering...

Improvements to the optimal control Newton-Raphson GRAPE method for exact Hessian calculations are shown with examples of auxiliary matrix and ESCALADE methods. For an ensemble two-level systems realistic MRI conditions, new accelerated between 200 600 times faster ESCALADE, respectively.

Single-spin vector effective Hamiltonian theory is proven to be a powerful theoretical framework analyse and develop pulsed DNP experiments.

A novel type of efficient broadband pulse, called second-order phase dispersion by optimised rotation (SORDOR), has recently been introduced. In contrast to adiabatic excitation, SORDOR-90 pulses provide effective transverse 90∘ rotations throughout their bandwidth, with a quadratic offset dependence the in x,y plane. Together phase-matched SORDOR-180 pulses, this enables Böhlen-Bodenhausen refocusing approach for linearly frequency-swept be extended any 90∘/180∘ pulse-delay sequence....

Developing fast, robust, and accurate methods for optimal control of quantum systems comprising interacting particles is one the most active areas current science. Although a valuable repository algorithms available numerical applications in control, high computational cost somewhat overlooked. Here, we present fast algorithm qubits, QOALA (quantum by adaptive low-cost algorithm), which predicted to offer [Formula: see text](M2) speedup an M-qubit system, compared state-of-the-art exact...

Dynamic nuclear polarization (DNP) has proven to be a powerful technique enhance spin by transferring the much higher electron spins prior detection. While major attention been devoted high-field applications with continuous microwave irradiation, introduction of fast arbitrary waveform generators is gradually increasing opportunities realization pulsed DNP. Here, we describe how static-powder DNP pulse sequences may systematically designed using single-spin vector effective Hamiltonian...

Work within this thesis advances optimal control algorithms for application to magnetic resonance systems. Specifically, presenting a quadratically convergent version of the gradient ascent pulse engineering method. The work is formulated in superoperator representation Liouville-von Neumann equation. A Newton-grape method developed using efficient calculation analytical second directional derivatives. scale with same complexity as methods that use only first Algorithms ensure...

We have recently demonstrated supervised deep learning methods for rapid generation of radiofrequency pulses in magnetic resonance imaging (https://doi.org/10.1002/mrm.27740, https://doi.org/10.1002/mrm.28667). Unlike the previous iterative optimization approaches, generate a pulse using fixed number floating-point operations - this is important MRI, where patient-specific preferably must be produced real time. However, requires vast training libraries, which generated traditional methods,...

To address the problems of instrumental imperfection and time-consuming experimental setup in electron spin resonance (ESR), we present ESR-POISE, a user-friendly software package for fully automated fast on-the-fly optimisation acquisition ESR experiments. This open-source interfaces with Bruker's Xepr allows scientists to run user-defined optimisations.

This work presents a new class of pulse to perform broadband universal rotation on two-level systems, independent the system preparation, using phase dispersion function. The authors present method optimal control avoid traps manifold, and find pulses half duration compared previous best pulses.

Abstract. A novel type of efficient broadband pulses, called SORDOR (second order phase dispersion by optimized rotation pulses), has recently been introduced. In contrast to adiabatic excitation, SORDOR-90 pulses provide effective transverse 90° rotations throughout their bandwidth, with a quadratic offset dependence the in x,y-plane. Together phase-matched SORDOR-180 this enables Böhlen-Bodenhausen spectroscopy approach for frequency-swept be extended any 90°/180° pulse-delay sequence....

In this paper, we consider the control of two qubit systems in presence a weak measurement. particular how Hamiltonian feedback can be applied to systems, both case where only one is measured, and joint measurement made qubits. We rate entanglement increased by using feedback, also information gathered about measuring other.

A Hessian based optimal control method is presented in Liouville space to mitigate previously undesirable polynomial scaling of computation time. This new method, an improvement the state-of-the-art Newton-Raphson GRAPE derived with respect two exact time-propagator derivative techniques: auxiliary matrix and ESCALADE methods. We observed that compared best current implementation for ensemble 2-level systems, realistic conditions, Hessians can be 4-200 70-600 times faster, respectively.