@article{Breitweiser2024,
title = {Quadrupolar resonance spectroscopy of individual nuclei using a room-temperature quantum sensor},
author = {S. Alex Breitweiser and Mathieu Ouellet and Tzu-Yung Huang and Tim H. Taminiau and Lee C. Bassett},
url = {https://arxiv.org/abs/2405.14859},
year = {2024},
date = {2024-06-05},
abstract = {Nuclear quadrupolar resonance (NQR) spectroscopy reveals chemical bonding patterns in materials and molecules through the unique coupling between nuclear spins and local fields. However, traditional NQR techniques require macroscopic ensembles of nuclei to yield a detectable signal, which precludes the study of individual molecules and obscures molecule-to-molecule variations due to local perturbations or deformations. Optically active electronic spin qubits, such as the nitrogen-vacancy (NV) center in diamond, facilitate the detection and control of individual nuclei through their local magnetic couplings. Here, we use NV centers to perform NQR spectroscopy on their associated nitrogen-14 (14N) nuclei at room temperature. In mapping the nuclear quadrupolar Hamiltonian, we resolve minute variations between individual nuclei. The measurements further reveal correlations between the parameters in the NV center's electronic spin Hamiltonian and the 14N quadropolar Hamiltonian, as well as a previously unreported Hamiltonian term that results from symmetry breaking. We further design pulse sequences to initialize, readout, and control the quantum evolution of the 14N nuclear state using the nuclear quadrupolar Hamiltonian.},
keywords = {},
pubstate = {forthcoming},
tppubtype = {article}
}

@article{Keneipp2024,
title = {Nanoscale Sculpting of Hexagonal Boron Nitride with an Electron Beam},
author = {Rachael N. Keneipp and Jordan A. Gusdorff and Pia Bhatia and Trey T. Shin and Lee C. Bassett and Marija Drndić},
url = {https://pubs.acs.org/doi/full/10.1021/acs.jpcc.4c02038},
doi = {10.1021/acs.jpcc.4c02038},
year = {2024},
date = {2024-05-17},
journal = {Journal of Physical Chemistry C},
volume = {128},
number = {21},
pages = {8741–8749},
abstract = {Creating sub- to few-nanometer defects and nanopores in hexagonal boron nitride (hBN) opens opportunities for engineering quantum emitters and for nanofluidic and sensing applications. Using the electron beam in the aberration-corrected scanning transmission electron microscope, we demonstrate modification, thinning, and drilling of features in few-layer hBN membranes (∼5 to 20 nm-thick). The atomic composition is monitored with electron energy loss spectroscopy, which also facilitates drift correction. We report effects of electron beam energy and exposure times on defect size and structure. While previous studies focused on beam energies of ≤80 keV to avoid material damage, we show that drilling is favorable at a higher beam energy of 200 keV. The drilling rate at 200 keV is about 10 times larger than at 80 keV (∼1.2 vs 0.1 nm/min), and smaller pores are achievable with minimized damage to the surrounding material. Thinned hBN nanoscale features demonstrate enhanced emission via photoluminescence spectroscopy.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Ouellet2024,
title = {Mechanical prions: Self-assembling microstructures},
author = {Mathieu Ouellet and Dani S. Bassett and Lee C. Bassett and Kieran A. Murphy and Shubhankar P. Patankar},
url = {https://arxiv.org/abs/2402.10939},
year = {2024},
date = {2024-04-16},
abstract = {Prions are misfolded proteins that transmit their structural arrangement to neighboring proteins. In biological systems, prion dynamics can produce a variety of complex functional outcomes. Yet, an understanding of prionic causes has been hampered by the fact that few computational models exist that allow for experimental design, hypothesis testing, and control. Here, we identify essential prionic properties and present a biologically inspired model of prions using simple mechanical structures capable of undergoing complex conformational change. We demonstrate the utility of our approach by designing a prototypical mechanical prion and validating its properties experimentally. Our work provides a design framework for harnessing and manipulating prionic properties in natural and artificial systems.},
keywords = {},
pubstate = {forthcoming},
tppubtype = {article}
}

@article{vandeStolpe2023,
title = {Mapping a 50-spin-qubit network through correlated sensing},
author = {G.L. van de Stolpe and D. P. Kwiatkowski and C.E. Bradley and J. Randall and S. A. Breitweiser and L. C. Bassett and M. Markham and D.J. Twitchen and T.H. Taminiau},
url = {https://arxiv.org/abs/2307.06939
https://www.nature.com/articles/s41467-024-46075-4},
doi = {10.1038/s41467-024-46075-4},
year = {2024},
date = {2024-03-05},
journal = {Nature Communications },
volume = {15},
number = {2006},
abstract = {Spins associated to optically accessible solid-state defects have emerged as a versatile platform for exploring quantum simulation, quantum sensing and quantum communication. Pioneering experiments have shown the sensing, imaging, and control of multiple nuclear spins surrounding a single electron-spin defect. However, the accessible size and complexity of these spin networks has been constrained by the spectral resolution of current methods. Here, we map a network of 50 coupled spins through high-resolution correlated sensing schemes, using a single nitrogen-vacancy center in diamond. We develop concatenated double-resonance sequences that identify spin-chains through the network. These chains reveal the characteristic spin frequencies and their interconnections with high spectral resolution, and can be fused together to map out the network. Our results provide new opportunities for quantum simulations by increasing the number of available spin qubits. Additionally, our methods might find applications in nano-scale imaging of complex spin systems external to the host crystal.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Gali2024,
title = {Challenges in advancing our understanding of atomic-like quantum systems: Theory and experiment},
author = {Adam Gali and André Schleife and Andreas J. Heinrich and Arne Laucht and Bruno Schuler and Chitraleema Chakraborty and Christopher P. Anderson and Corentin Déprez and Jeffrey McCallum and Lee C. Bassett and Mark Friesen and Michael E. Flatté and Peter Maurer and Susan N. Coppersmith and Tian Zhong and Vijaya Begum-Hudde and Yuan Ping },
url = {https://link.springer.com/article/10.1557/s43577-023-00659-5},
doi = {10.1557/s43577-023-00659-5},
year = {2024},
date = {2024-02-14},
journal = {MRS Bulletin},
volume = {49},
pages = {256-276},
abstract = {Quantum information processing and quantum sensing is a central topic for researchers who are part of the Materials Research Society and the Quantum Staging Group is providing leadership and guidance in this context. We convened a workshop before the 2022 MRS Spring Meeting and covered four topics to explore challenges that need to be addressed to further promote and accelerate the development of materials with applications in quantum technologies. This article captures the discussions at this workshop and refers to the pertinent literature.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}