Strong Interactions of Single Atoms and Photons near a Dielectric Boundary

Modern research in optical physics has achieved quantum control of strong interactions between a single atom and one photon within the setting of cavity quantum electrodynamics (cQED). However, to move beyond current proof-of-principle experiments involving one or two conventional optical cavities to more complex scalable systems that employ N >> 1 microscopic resonators requires the localization of individual atoms on distance scales < 100 nm from a resonator's surface. In this regime an atom can be strongly coupled to a single intracavity photon while at the same time experiencing significant radiative interactions with the dielectric boundaries of the resonator. Here, we report an initial step into this new regime of cQED by way of real-time detection and high-bandwidth feedback to select and monitor single Cesium atoms localized ~100 nm from the surface of a micro-toroidal optical resonator. We employ strong radiative interactions of atom and cavity field to probe atomic motion through the evanescent field of the resonator. Direct temporal and spectral measurements reveal both the significant role of Casimir-Polder attraction and the manifestly quantum nature of the atom-cavity dynamics. Our work sets the stage for trapping atoms near micro- and nano-scopic optical resonators for applications in quantum information science, including the creation of scalable quantum networks composed of many atom-cavity systems that coherently interact via coherent exchanges of single photons.Comment: 8 pages, 5 figures, Supplemental Information included as ancillary fil

Long-term efficacy of spa therapy in patients with rheumatoid arthritis

Our previous crossover randomized trial suggested that spa therapy added to usual pharmacotherapy provides benefits that lasted 6 months over pharmacotherapy alone in rheumatoid arthritis patients. We now extend, and report the long-term results of that study. In the crossover trial, patients were randomized to spa therapy first group or control first group (first assignment, period 1, 6 months); after this period and washout phase (9 months), they crossed over to the other arm (second assignment, period 2, 6 months). In this long-term study, we now analyze the 15-month results of the first assignment, and 12-month results of the second assignment in the opposite side with a 6-month extension of the follow-up period. The clinical outcome measures were pain, patient and physician global assessment, Health Assessment Questionnaire, and Disease Activity Score-28. The 15-month results of first assignment revealed no statistically significant differences between the groups in any of the efficacy outcomes (p > 0.05 for all). The 12-month results for the second assignment after crossover revealed a statistically significant decrease between the groups regarding the patient global assessment scores (p = 0.016), physician global assessment scores (p = 0.003) and swollen joints counts (p = 0.030); however, no statistically significant difference was found between the groups in any of the other efficacy outcomes (p > 0.05 for all). The short- and medium-term beneficial effects of the 2-week spa therapy added to the usual pharmacotherapy observed through the initial 6-month evaluation period may be maintained mildly to moderately to the 12-month mark in rheumatoid arthritis patients receiving conventional disease-modifying antirheumatic drugs. Further studies with a larger sample size are needed for the confirmation of the study results