Tootfinder

Fisher's approach to deformation of coactions
Alcides Buss, Siegfried Echterhoff
https://arxiv.org/abs/2507.03563 https://arxiv.o…

Fisher's approach to deformation of coactions
This paper explores a novel approach to the deformation of $C^*$-algebras via coactions of locally compact groups, emphasizing Fischer's construction in the context of maximal coactions. We establish a rigorous framework for understanding how deformations arise from group coactions, extending previous work by Bhowmick, Neshveyev, and Sangha. Using Landstad duality, we compare different deformation procedures, demonstrating their equivalence and efficiency in constructing twisted versions of giv…

Impedance-tuned microwave loop for fast, homogeneous Rabi oscillations of a dense ensemble of NV-diamond electronic spins
Han Sae Jung, Johannes Cremer, Aoyang Zhang, Sangha Kim, Guang Yang, Ronald L. Walsworth, Donhee Ham
https://arxiv.org/abs/2507.17689

Impedance-tuned microwave loop for fast, homogeneous Rabi oscillations of a dense ensemble of NV-diamond electronic spins
Obtaining a high Rabi oscillation frequency homogeneously across a spatially-extended population of nitrogen-vacancy (NV) center electronic spins in diamond is useful for efficient spin-state manipulation of the NV ensemble and in using NVs to detect ensembles of other spin species. Here, we achieve a high, homogeneous Rabi frequency for a dense NV ensemble by enhancing the microwave magnetic fields in the center region of a diamond-coupled planar metallic loop via systematic engineering that i…