Controlling effective Hamiltonians: Broadband pulsed dynamic nuclear polarization by constrained random walk and non-linear optimization

A Anders B. Nielsen (Interdisciplinary Nanoscience Center (iNANO) and Department of Chemistry) J José P. Carvalho (Department of Materials and Environmental Chemistry) N Nino Wili (Interdisciplinary Nanoscience Center (iNANO) and Department of Chemistry, Aarhus University 1 , Gustav Wieds Vej 14, DK-8000 Aarhus C,) F Filip V. Jensen (Interdisciplinary Nanoscience Center (iNANO) and Department of Chemistry, Aarhus University 1 , Gustav Wieds Vej 14, DK-8000 Aarhus C,) D David L. Goodwin (Interdisciplinary Nanoscience Center (iNANO) and Department of Chemistry, Aarhus University 1 , Gustav Wieds Vej 14, DK-8000 Aarhus C,) T Thomas S. Untidt (Interdisciplinary Nanoscience Center (iNANO) and Department of Chemistry, Aarhus University 1 , Gustav Wieds Vej 14, DK-8000 Aarhus C,) Z Zdeněk Tošner (Department of Chemistry, Faculty of Science, Charles University 2 , Hlavova 8, Prague CZ-128 43,) N Niels Chr. Nielsen (Interdisciplinary Nanoscience Center (iNANO) and Department of Chemistry)

Abstract

We present constrained random walk (cRW) and figure of merit (FOM) based non-linear optimization procedures for systematic design and fundamental understanding of magnetic resonance experiments, addressing bilinear and linear effective Hamiltonians to provide broadband polarization transfer. cRW can be used directly for fast random experiment design or in combination with non-linear optimization or optimal control, leveraging the optimization of a FOM function for efficient control of linear and bilinear terms derived by exact effective Hamiltonian theory. The efficacy of the combined cRW and FOM-based optimization approach is demonstrated by the design of broadband dynamic nuclear polarization pulse sequences for static solids with an electron spin excitation bandwidth reaching 100 MHz.

Article Details

Volume / Issue Vol. 163, Issue 14
Published October 14, 2025
ISSN 0021-9606
Publisher American Institute of Physics

Journal Info

The Journal of Chemical Physics

American Institute of Physics

ISSN: 0021-9606 Physical Sciences

Authors (8)

A

Anders B. Nielsen

Interdisciplinary Nanoscience Center (iNANO) and Department of Chemistry

J

José P. Carvalho

Department of Materials and Environmental Chemistry

N

Nino Wili

Interdisciplinary Nanoscience Center (iNANO) and Department of Chemistry, Aarhus University 1 , Gustav Wieds Vej 14, DK-8000 Aarhus C,

F

Filip V. Jensen

Interdisciplinary Nanoscience Center (iNANO) and Department of Chemistry, Aarhus University 1 , Gustav Wieds Vej 14, DK-8000 Aarhus C,

D

David L. Goodwin

Interdisciplinary Nanoscience Center (iNANO) and Department of Chemistry, Aarhus University 1 , Gustav Wieds Vej 14, DK-8000 Aarhus C,

T

Thomas S. Untidt

Interdisciplinary Nanoscience Center (iNANO) and Department of Chemistry, Aarhus University 1 , Gustav Wieds Vej 14, DK-8000 Aarhus C,

Z

Zdeněk Tošner

Department of Chemistry, Faculty of Science, Charles University 2 , Hlavova 8, Prague CZ-128 43,

N

Niels Chr. Nielsen

Interdisciplinary Nanoscience Center (iNANO) and Department of Chemistry