Optimally shaped terahertz pulses for phase retrieval in a Rydberg atom data register

We employ Optimal Control Theory to discover an efficient information retrieval algorithm that can be performed on a Rydberg atom data register using a shaped terahertz pulse. The register is a Rydberg wave packet with one consituent orbital phase-reversed from the others (the ``marked bit''). The terahertz pulse that performs the decoding algorithm does so by by driving electron probability density into the marked orbital. Its shape is calculated by modifying the target of an optimal control problem so that it represents the direct product of all correct solutions to the algorithm.Comment: 6 pages, 3 figure

Generation of atom-photon entangled states in atomic Bose-Einstein condensate via electromagnetically induced transparency

In this paper, we present a method to generate continuous-variable-type entangled states between photons and atoms in atomic Bose-Einstein condensate (BEC). The proposed method involves an atomic BEC with three internal states, a weak quantized probe laser and a strong classical coupling laser, which form a three-level Lambda-shaped BEC system. We consider a situation where the BEC is in electromagnetically induced transparency (EIT) with the coupling laser being much stronger than the probe laser. In this case, the upper and intermediate levels are unpopulated, so that their adiabatic elimination enables an effective two-mode model involving only the atomic field at the lowest internal level and the quantized probe laser field. Atom-photon quantum entanglement is created through laser-atom and inter-atomic interactions, and two-photon detuning. We show how to generate atom-photon entangled coherent states and entangled states between photon (atom) coherent states and atom-(photon-) macroscopic quantum superposition (MQS) states, and between photon-MQS and atom-MQS states.Comment: 9 pages, 1 figur

COVID-19 and Canadian Gastroenterology Trainees.

Background The coronavirus disease 2019 (COVID-19) pandemic has impacted endoscopy services and education worldwide. This study aimed to characterize the impact of COVID-19 on gastroenterology trainees in Canada. Methods An analysis of Canadian respondents from the international EndoTrain survey, open from April 11 to May 2 2020 and distributed by program directors, trainees, and national and international gastroenterology societies' representatives, was completed. The survey included questions on monthly endoscopy volume, personal protective equipment availability, trainee well-being and educational resources. The primary outcome was change in procedural volume during the COVID-19 pandemic. Secondary outcomes included trainee's professional and personal concerns, anxiety and burnout. Results Thirty-four Canadian trainees completed the survey. Per month, participants completed a median of 30 esophagogastroduodenoscopies (interquartile range 16 to 50) prior to the pandemic compared to 2 (0 to 10) during the pandemic, 20 (8 to 30) compared to 2 (0 to 5) colonoscopies and 3 (1 to 10) compared to 0 (0 to 3) upper gastrointestinal bleeding procedures. There was a significant decrease in procedural volumes between the pre-COVID-19 and COVID-19 time periods for all procedures ( < 0.001). Thirty (88%) trainees were concerned about personal COVID-19 exposure, 32 (94%) were concerned about achieving and/or maintaining clinical competence and 24 (71%) were concerned about prolongation of training time due to the pandemic. Twenty-six (79%) respondents experienced some degree of anxiety, and 10 (31%) experienced some degree of burnout. Conclusion The COVID-19 pandemic has substantially impacted gastroenterology trainees in Canada. As the pandemic eases, it important for gastrointestinal programs to adapt to maximize resident learning, maintain effective clinical care and ensure development of endoscopic competence