Narrow-line Laser Cooling by Adiabatic Transfer

We propose and demonstrate a novel laser cooling mechanism applicable to particles with narrow-linewidth optical transitions. By sweeping the frequency of counter-propagating laser beams in a sawtooth manner, we cause adiabatic transfer back and forth between the ground state and a long-lived optically excited state. The time-ordering of these adiabatic transfers is determined by Doppler shifts, which ensures that the associated photon recoils are in the opposite direction to the particle's motion. This ultimately leads to a robust cooling mechanism capable of exerting large forces via a weak transition and with reduced reliance on spontaneous emission. We present a simple intuitive model for the resulting frictional force, and directly demonstrate its efficacy for increasing the total phase-space density of an atomic ensemble. We rely on both simulation and experimental studies using the 7.5~kHz linewidth $^1$S$_0$ to $^3$P$_1$ transition in $^{88}$Sr. The reduced reliance on spontaneous emission may allow this adiabatic sweep method to be a useful tool for cooling particles that lack closed cycling transitions, such as molecules.Comment: 5 pages, 4 figure

Object Lessons: 3D Printing and Inter-professional Collaboration Between the Library and the Literature Classroom

While the digital revolution has been readily embraced by the hard sciences, adoption by the humanities has been somewhat more delayed. A number of factors have prevented wide-scale inclusion of technology into humanities coursework including, but not limited to, a lack of training, resources or support for professional development. The new Makerspace at the Drake Memorial Library provided the chance to unite 3D printing technology, pedagogy, literary criticism, information literacy, and historical context into a children’s literature course at the College at Brockport. Students were charged to locate a single object from a work of children’s literature and to analyze its importance to the plot of the novel or the development of a character. Selected objects were then 3D printed by the library Makerspace. Students then met with a librarian to reinforce threshold concepts set forth by ACRL’s Framework for Information Literacy for Higher Education through a unique gamified Harry Potter - themed lesson. Students were able to successfully synthesize the relationship between object and text, culminating in the display of their objects in the library along with their written assignments

Extradural spinal cavernous angiomas: report of seven cases

Abstract The authors describe seven cases of extradural spinal cavernous angioma. Although cavernoma itself is not rare, the extradural spinal localization is uncommon and makes preoperative differential diagnosis difficult. Routine MRI investigation has aided neurosurgeons in evaluating the true incidence of these vascular malformations, which was understimated in the past. The data published so far have not entirely clarified the treatment of choice for these lesions. Considering their rarity in this site, their presenting symptoms and the difficulties involved in neuroradiological diagnosis, the authors discuss the role of surgery as the principal form of treatment and review the relevant literature. Seven patients (4 male, 3 female) were admitted to our Institute of Neurosurgery between 1992 and 2004, with a 5-6 month history (range=2-365 days) of low back pain or radicular pain, sometimes associated with paresthesia. All patients had a CT scan, as well as MRI with gadolinium when possible, which detected an extradural roundish lesion: differential diagnosis was very difficult, especially between neurinoma and cavernoma. Treatment was always surgical and resection of the lesion radical. Postoperatively, all patients presented complete regression of clinical symptoms. In all cases histological diagnosis was cavernous angioma. Postoperative MRI with gadolinium or CT scan with IV contrast, performed before discharge, confirmed radical removal of the vascular malformation in all cases. Our experience confirms that surgery should be the treatment of choice for these lesions, in view of both their tendency to bleed and their straightforward surgical removal

A tweezer clock with half-minute atomic coherence at optical frequencies and high relative stability

The preparation of large, low-entropy, highly coherent ensembles of identical quantum systems is foundational for many studies in quantum metrology, simulation, and information. Here, we realize these features by leveraging the favorable properties of tweezer-trapped alkaline-earth atoms while introducing a new, hybrid approach to tailoring optical potentials that balances scalability, high-fidelity state preparation, site-resolved readout, and preservation of atomic coherence. With this approach, we achieve trapping and optical clock excited-state lifetimes exceeding $40$ seconds in ensembles of approximately $150$ atoms. This leads to half-minute-scale atomic coherence on an optical clock transition, corresponding to quality factors well in excess of $10^{16}$. These coherence times and atom numbers reduce the effect of quantum projection noise to a level that is on par with leading atomic systems, yielding a relative fractional frequency stability of $5.2(3)\times10^{-17}~(\tau/s)^{-1/2}$ for synchronous clock comparisons between sub-ensembles within the tweezer array. When further combined with the microscopic control and readout available in this system, these results pave the way towards long-lived engineered entanglement on an optical clock transition in tailored atom arrays.Comment: 11 pages, 5 figures (main text); 17 pages, 7 figures (supplemental materials