Deterministic nano-assembly of a coupled quantum emitter - photonic crystal cavity system

The interaction of a single quantum emitter with its environment is a central theme in quantum optics. When placed in highly confined optical fields, such as those created in optical cavities or plasmonic structures, the optical properties of the emitter can change drastically. In particular, photonic crystal (PC) cavities show high quality factors combined with an extremely small mode volume. Efficiently coupling a single quantum emitter to a PC cavity is challenging because of the required positioning accuracy. Here, we demonstrate deterministic coupling of single Nitrogen-Vacancy (NV) centers to high-quality gallium phosphide PC cavities, by deterministically positioning their 50 nm-sized host nanocrystals into the cavity mode maximum with few-nanometer accuracy. The coupling results in a 25-fold enhancement of NV center emission at the cavity wavelength. With this technique, the NV center photoluminescence spectrum can be reshaped allowing for efficient generation of coherent photons, providing new opportunities for quantum science.Comment: 13 pages, 4 figure

Trusting AI: Integrating Artificial Intelligence into the Army’s Professional Expert Knowledge

Integrating artificially intelligent technologies for military purposes poses a special challenge. In previous arms races, such as the race to atomic bomb technology during World War II, expertise resided within the Department of Defense. But in the artificial intelligence (AI) arms race, expertise dwells mostly within industry and academia. Also, unlike the development of the bomb, effective employment of AI technology cannot be relegated to a few specialists; almost everyone will have to develop some level of AI and data literacy. Complicating matters is AI-driven systems can be a “black box” in that humans may not be able to explain some output, much less be held accountable for its consequences. This inability to explain coupled with the cession to a machine of some functions normally performed by humans risks the relinquishment of some jurisdiction and, consequently, autonomy to those outside the profession. Ceding jurisdiction could impact the American people’s trust in their military and, thus, its professional standing. To avoid these outcomes, creating and maintaining trust requires integrating knowledge of AI and data science into the military’s professional expertise. This knowledge covers both AI technology and how its use impacts command responsibility; talent management; governance; and the military’s relationship with the US government, the private sector, and society.https://press.armywarcollege.edu/monographs/1955/thumbnail.jp

Army Professionalism, the Military Ethic, and Officership in the 21st Century

The authors address what they—and many others—perceived to be a decline in military professionalism in the Army officer corps. The authors first describe the ethical, technical, and political components of military professionalism and then address the causes for the decline. They conclude by proposing a set of principles which, if adhered to, will reinvigorate the vision of the officer corps and motivate the corps to selfless service.https://press.armywarcollege.edu/monographs/1145/thumbnail.jp

The Use of Statistics in Experimental Physics

Most mathematicians are aware of the importance of statistics in biological sciences, business, and economics, but are less aware that statistics is used every day in experimental physics. This paper gives three interesting examples of how statistics plays a vital role in physics. These examples use the basic statistical tools of residuals analysis and goodness of fit

Imaging radar observations of Farley Buneman waves during the JOULE II experiment

Vector electric fields and associated <I><B>E</B></I>×<I><B>B</B></I> drifts measured by a sounding rocket in the auroral zone during the NASA JOULE II experiment in January 2007, are compared with coherent scatter spectra measured by a 30 MHz radar imager in a common volume. Radar imaging permits precise collocation of the spectra with the background electric field. The Doppler shifts and spectral widths appear to be governed by the cosine and sine of the convection flow angle, respectively, and also proportional to the presumptive ion acoustic speed. The neutral wind also contributes to the Doppler shifts. These findings are consistent with those from the JOULE I experiment and also with recent numerical simulations of Farley Buneman waves and instabilities carried out by Oppenheim et al. (2008). Simple linear analysis of the waves offers some insights into the spectral moments. A formula relating the spectral width to the flow angle, ion acoustic speed, and other ionospheric parameters is derived