Showing papers by "Steffen J. Glaser published in 2022"
TL;DR: In this article , the authors review recent progress in understanding of the controllability of open quantum systems and in the development and application of quantum control techniques to quantum technologies, and sketch a roadmap for future developments.
Abstract: Quantum optimal control, a toolbox for devising and implementing the shapes of external fields that accomplish given tasks in the operation of a quantum device in the best way possible, has evolved into one of the cornerstones for enabling quantum technologies. The last few years have seen a rapid evolution and expansion of the field. We review here recent progress in our understanding of the controllability of open quantum systems and in the development and application of quantum control techniques to quantum technologies. We also address key challenges and sketch a roadmap for future developments.
102 citations
TL;DR: In this article , the authors review recent progress in understanding of the controllability of open quantum systems and in the development and application of quantum control techniques to quantum technologies, and sketch a roadmap for future developments.
Abstract: Quantum optimal control, a toolbox for devising and implementing the shapes of external fields that accomplish given tasks in the operation of a quantum device in the best way possible, has evolved into one of the cornerstones for enabling quantum technologies. The last few years have seen a rapid evolution and expansion of the field. We review here recent progress in our understanding of the controllability of open quantum systems and in the development and application of quantum control techniques to quantum technologies. We also address key challenges and sketch a roadmap for future developments.
48 citations
TL;DR: In this paper , the authors used a dense, shallow ensemble of N-$V$ centers to demonstrate polarization transfer to nuclear spins in a well-defined composite diamond sample system, and they showed that using spinlock pulses, the inhomogeneously broadened electron spin resonance line of the ensemble limits the minimal resonance linewidth with which the transfer protocol can occur.
Abstract: Nitrogen-vacancy (N-$V$) diamonds have attracted keen interest for nanoscale sensing and spin manipulation. In particular, the nonequilibrium electron spin polarization after optical excitation of single N-$V$ centers has successfully been transferred to nuclear spin baths in the surrounding of defects. However, these experiments need to be extended to N-$V$ ensembles that have promising practical applications in the hyperpolarization of bulk sample volumes for NMR signal enhancement. Here, we use a dense, shallow ensemble of N-$V$ centers to demonstrate polarization transfer to nuclear spins in a well-defined composite diamond sample system. This allows us to address three different types of nuclear spins in different positions with respect to the N-$V$ polarization source: from the close proximity of ${}^{13}\mathrm{C}$ inside the diamond lattice to the self-assembled molecular system consisting of ${}^{1}\mathrm{H}$ and ${}^{19}\mathrm{F}$ spins outside the diamond and over multiple interfaces. We show that ensemble N-$V$ experiments face problems different from single N-$V$ experiments. In particular, using spinlock pulses, the inhomogeneously broadened electron spin resonance line of the N-$V$ ensemble limits the minimal resonance linewidth with which the transfer protocol can occur. Furthermore, we compare the N-$V$ spin-polarization losses and polarization transfer rates to the different nuclear baths and discuss the role of spin diffusion as detrimentally affecting the direct observation of nuclear polarization buildup within the detection volume of nanoscale N-$V$-NMR experiments.
10 citations